@article{lewis_battye_aneja_kim_bell_2023, title={Modeling and Analysis of Air Pollution and Environmental Justice: The Case for North Carolina's Hog Concentrated Animal Feeding Operations}, volume={131}, ISSN={["1552-9924"]}, DOI={10.1289/EHP11344}, abstractNote={Background: Concentrated animal feeding operations (CAFOs) emit pollutants that can cause negative impacts on human health. The concentration of hog production in North Carolina raises concerns regarding the disproportionate exposure of vulnerable communities to air pollution from CAFOs. Objectives: We investigated whether exposure to gaseous ammonia (NH3) and hydrogen sulfide (H2S) (in 2019) differs between subpopulations by examining demographics, including race/ethnicity, age, educational attainment, language proficiency, and socioeconomic status. Methods: We used an Air Monitoring Station (AMS)/Environmental Protection Agency (EPA) Regulatory Model (AERMOD)–based Human Exposure Model (version 3) to estimate ambient concentrations of NH3 and H2S from hog farms in Duplin County and its surrounding counties in North Carolina and estimate subsequent exposures of communities within 50km of Duplin County, North Carolina, or the Duplin County Region. We combined estimated exposures with 2016 American Community Summary Census data, at the block group level, using spatial analysis to investigate whether exposures to these pollutants differ by race and ethnicity, age, income, education, and language proficiency. Based on these estimations, we assessed associated exposure risks to the impacted communities and used multivariable regression modeling to evaluate the relationship between average ammonia exposures from Duplin regional hog farms and the presence of vulnerable populations. Results: The average [±standard deviation (SD)] annual estimated concentration of NH3 and H2S in the Duplin County Region is 1.75±2.81 μg/m3 and 0.0087±0.014 μg/m3, respectively. The maximum average annual ambient concentrations are estimated at 54.27±4.12 μg/m3 and 0.54±0.041 μg/m3 for NH3 and H2S, respectively. Our descriptive analysis reveals that people of low income, people of color, people with low educational attainment, and the linguistically isolated in the Duplin Region are disproportionately exposed to higher levels of pollutants than the average exposure for residents. Alternatively, our statistical results suggests that after adjusting for covariates, communities of color are associated with 1.70% (95% CI: −3.79, 0.44) lower NH3 concentrations per 1-SD increase. One-standard deviation increases in the adults with low educational attainment and children <19 years of age is associated with 1.26% (95% CI: −0.77, 3.33) and 1.20% (95% CI: −0.62, 3.05) higher NH3 exposure per 1-SD increase, respectively. Discussion: Exposures to NH3 and H2S differed by race and ethnicity, educational attainment, language proficiency, and socioeconomic status. The observed associations between exposure to CAFO-generated pollutants and sociodemographic indicators differed among demographics. The disproportionate distribution of hog facilities and resulting pollutant exposures among communities may have adverse environmental and human health impacts, raising environmental justice concerns. https://doi.org/10.1289/EHP11344}, number={8}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Lewis, Brandon M. and Battye, William H. and Aneja, Viney P. and Kim, Honghyok and Bell, Michelle L.}, year={2023}, month={Aug} }
 @article{akdemir_battye_myers_aneja_2022, title={Estimating NH3 and PM2.5 emissions from the Australia mega wildfires and the impact of plume transport on air quality in Australia and New Zealand}, volume={2}, ISSN={["2634-3606"]}, DOI={10.1039/d1ea00100k}, abstractNote={HYSPLIT modeling analysis. Long-range transport of PM2.5. Emissions of ammonia and PM2.5 from biomass burning.}, number={4}, journal={ENVIRONMENTAL SCIENCE-ATMOSPHERES}, author={Akdemir, Ece Ari and Battye, William H. and Myers, Casey Bray and Aneja, Viney P.}, year={2022}, month={Jul}, pages={634–646} }
 @article{akdemir_battye_myers_aneja_2022, title={Estimating NH3 and PM2.5 emissions from the Australia mega wildfires and the impact of plume transport on air quality in Australia and New Zealand (Jun, 10.1039/d1ea00100k, 2022)}, volume={6}, ISSN={["2634-3606"]}, DOI={10.1039/d2ea90015g}, abstractNote={Correction for ‘Estimating NH3 and PM2.5 emissions from the Australia mega wildfires and the impact of plume transport on air quality in Australia and New Zealand’ by Ece Ari Akdemir et al., Environ. Sci.: Atmos., 2022, https://doi.org/10.1039/d1ea00100k.}, journal={ENVIRONMENTAL SCIENCE-ATMOSPHERES}, author={Akdemir, Ece Ari and Battye, William H. and Myers, Casey Bray and Aneja, Viney P.}, year={2022}, month={Jun} }
 @article{wiegand_battye_myers_aneja_2022, title={Particulate Matter and Ammonia Pollution in the Animal Agricultural-Producing Regions of North Carolina: Integrated Ground-Based Measurements and Satellite Analysis}, volume={13}, ISSN={["2073-4433"]}, DOI={10.3390/atmos13050821}, abstractNote={Intensive animal agriculture is an important part of the US and North Carolina’s (NC’s) economy. Large emissions of ammonia (NH3) gas emanate from the handling of animal wastes at these operations contributing to the formation of fine particulate matter (PM2.5) around the state causing a variety of human health and environmental effects. The objective of this research is to provide the relationship between ammonia, aerosol optical depth and meteorology and its effect on PM2.5 concentrations using satellite observations (column ammonia and aerosol optical depth (AOD)) and ground-based meteorological observations. An observational-based multiple linear regression model was derived to predict ground-level PM2.5 during the summer months (JJA) from 2008–2017 in New Hanover County, Catawba County and Sampson County. A combination of the Cumberland and Johnston County models for the summer was chosen and validated for Duplin County, NC, then used to predict Sampson County, NC, PM2.5 concentrations. The model predicted a total of six 24 h exceedances over the nine-year period. This indicates that there are rural areas of the state that may have air quality issues that are not captured for a lack of measurements. Moreover, PM2.5 chemical composition analysis suggests that ammonium is a major component of the PM2.5 aerosol.}, number={5}, journal={ATMOSPHERE}, author={Wiegand, Rebecca and Battye, William H. and Myers, Casey Bray and Aneja, Viney P.}, year={2022}, month={May} }
 @article{hallar_brown_crosman_barsanti_cappa_faloona_fast_holmes_horel_lin_et al._2021, title={Coupled Air Quality and Boundary-Layer Meteorology in Western US Basins during Winter: Design and Rationale for a Comprehensive Study}, volume={102}, ISSN={["1520-0477"]}, DOI={10.1175/BAMS-D-20-0017.1}, abstractNote={Wintertime episodes of high aerosol concentrations occur frequently in urban and agricultural basins and valleys worldwide. These episodes often arise following development of persistent cold-air pools (PCAPs) that limit mixing and modify chemistry. While field campaigns targeting either basin meteorology or wintertime pollution chemistry have been conducted, coupling between interconnected chemical and meteorological processes remains an insufficiently studied research area. Gaps in understanding the coupled chemical-meteorological interactions that drive high pollution events make identification of the most effective air-basin specific emission control strategies challenging. To address this, a September 2019 workshop occurred with the goal of planning a future research campaign to investigate air quality in Western U.S. basins. Approximately 120 people participated, representing 50 institutions and 5 countries. Workshop participants outlined the rationale and design for a comprehensive wintertime study that would couple atmospheric chemistry and boundary-layer and complex-terrain meteorology within western U.S. basins. Participants concluded the study should focus on two regions with contrasting aerosol chemistry: three populated valleys within Utah (Salt Lake, Utah, and Cache Valleys) and the San Joaquin Valley in California. This paper describes the scientific rationale for a campaign that will acquire chemical and meteorological datasets using airborne platforms with extensive range, coupled to surface-based measurements focusing on sampling within the near-surface boundary layer, and transport and mixing processes within this layer, with high vertical resolution at a number of representative sites. No prior wintertime basin-focused campaign has provided the breadth of observations necessary to characterize the meteorological-chemical linkages outlined here, nor to validate complex processes within coupled atmosphere-chemistry models.}, number={10}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Hallar, A. Gannet and Brown, Steven S. and Crosman, Erik and Barsanti, Kelley and Cappa, Christopher D. and Faloona, Ian and Fast, Jerome and Holmes, Heather A. and Horel, John and Lin, John and et al.}, year={2021}, month={Oct}, pages={E2012–E2033} }
 @article{bray_battye_aneja_schlesinger_2021, title={Global emissions of NH3, NOx, and N2O from biomass burning and the impact of climate change}, volume={71}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85097371854&partnerID=MN8TOARS}, DOI={10.1080/10962247.2020.1842822}, abstractNote={ABSTRACT Emissions of ammonia (NH3), oxides of nitrogen (NOx; NO +NO2), and nitrous oxide (N2O) from biomass burning were quantified on a global scale for 2001 to 2015. On average biomass burning emissions at a global scale over the period were as follows: 4.53 ± 0.51 Tg NH3 year−1, 14.65 ± 1.60 Tg NOx year−1, and 0.97 ± 0.11 Tg N2O year−1. Emissions were comparable to other emissions databases. Statistical regression models were developed to project NH3, NOx, and N2O emissions from biomass burning as a function of burn area. Two future climate scenarios (RCP 4.5 and RCP 8.5) were analyzed for 2050–2055 (“mid-century”) and 2090–2095 (“end of century”). Under the assumptions made in this study, the results indicate emissions of all species are projected to increase under both the RCP 4.5 and RCP 8.5 climate scenarios. Implications: This manuscript quantifies emissions of NH3, NOx, and N2O on a global scale from biomass burning from 2001–2015 then creates regression models to predict emissions based on climate change. Because reactive nitrogen emissions have such an important role in the global nitrogen cycle, changes in these emissions could lead to a number of health and environmental impacts.}, number={1}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Bray, Casey D. and Battye, William H. and Aneja, Viney P. and Schlesinger, William H.}, year={2021}, month={Jan}, pages={102–114} }
 @article{bray_nahas_battye_aneja_2021, title={Impact of lockdown during the COVID-19 outbreak on multi-scale air quality}, volume={254}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85104410171&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2021.118386}, abstractNote={One of the multi-facet impacts of lockdowns during the unprecedented COVID-19 pandemic was restricted economic and transport activities. This has resulted in the reduction of air pollution concentrations observed globally. This study is aimed at examining the concentration changes in air pollutants (i.e., carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and particulate matters (PM2.5 and PM10) during the period March-April 2020. Data from both satellite observations (for NO2) and ground-based measurements (for all other pollutants) were utilized to analyze the changes when compared against the same months between 2015 and 2019. Globally, space borne NO2 column observations observed by satellite (OMI on Aura) were reduced by approximately 9.19% and 9.57%, in March and April 2020, respectively because of public health measures enforced to contain the coronavirus disease outbreak (COVID-19). On a regional scale and after accounting for the effects of meteorological variability, most monitoring sites in Europe, USA, China, and India showed declines in CO, NO2, SO2, PM2.5, and PM10 concentrations during the period of analysis. An increase in O3 concentrations occurred during the same period. Meanwhile, four major cities case studies i.e. in New York City (USA), Milan (Italy), Wuhan (China), and New Delhi (India) have also shown a similar reduction trends as observed on the regional scale, and an increase in ozone concentration. This study highlights that the reductions in air pollutant concentrations have overall improved global air quality likely driven in part by economic slowdowns resulting from the global pandemic.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Bray, Casey D. and Nahas, Alberth and Battye, William H. and Aneja, Viney P.}, year={2021}, month={Jun} }
 @article{uttamang_campbell_aneja_hanna_2020, title={A multi-scale model analysis of ozone formation in the Bangkok Metropolitan Region, Thailand}, volume={229}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85083337226&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2020.117433}, abstractNote={Over the last three decades, Thailand's rapid industrialization and urbanization have led to an impact on urban air quality. A majority of the country's development has occurred within and around Bangkok (BKK), the capital city of Thailand, and the Bangkok Metropolitan Region (BMR). Since 1995, the BMR has experienced air quality degradation, in particular, enhanced ozone (O3) due to a combination of the local increase in emissions from accelerated growth in automotive and industrial activities, local meteorology including strong solar radiation, high temperature and high humidity, and potential long-range effects of regional transport from China. To investigate the O3 formation in the BMR due to the effects of long-range transport and local meteorology feedbacks, we perform a multi-scale simulation with the Weather Research and Forecasting model with Chemistry (WRF-Chem) during the O3 season (January to March), 2010; since O3 mixing ratio exceedances in the BMR occur primarily during this period The results in this study indicate the significance of China's emission reductions on the regional-scale and the local-scale pollution, as far as the BMR region and southern Thailand. Applying China's oxide of nitrogen (NOx)-only emission controls, generally, enhance the domain-wide monthly-average peroxyacetyl nitrate (PAN) and O3 in the regional scale, in the order of ~1–7% and ~1–5%, respectively, while those in the local scale are ~ 0.2–6% and ~0.1–5% compared with the baseline simulation. However, the increases in PAN and O3 are mitigated by 40% China's Volatile Organic Compound (VOC) reduction along with 40% NOx reduction. The results, supported by an indicator analysis, suggest that northern and eastern China, northern and central Thailand and the BMR, are likely VOC-limited during the O3 season. Since the BMR is VOC-limited regime, controlling anthropogenic VOC emissions will show more benefit to control O3 than controlling NOx-only emissions. Other factors that influence on O3 levels in the BMR are biogenic VOC emissions from the Tenasserim range and land- and sea-breeze circulations that recirculate and disperse pollutants along the coastal areas.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Uttamang, Pornpan and Campbell, Patrick C. and Aneja, Viney P. and Hanna, Adel F.}, year={2020}, month={May} }
 @article{aneja_schlesinger_li_nahas_battye_2020, title={Characterization of the Global Sources of Atmospheric Ammonia from Agricultural Soils}, volume={125}, ISSN={["2169-8996"]}, url={https://doi.org/10.1029/2019JD031684}, DOI={10.1029/2019JD031684}, abstractNote={Global ammonia (NH3) emissions to the atmosphere are projected to increase in the coming years with the increased use of synthetic nitrogen fertilizers and cultivation of nitrogen‐fixing crops. A statistical model (NH3_STAT) is developed for characterizing atmospheric NH3 emissions from agricultural soils and compared to the performance of other global and regional NH3 models (e.g., Emission Database for Global Atmospheric Research, Magnitude and Seasonality of Agricultural Emissions, MIX, and U.S. Environmental Protection Agency). The statistical model was developed from a multiple linear regression between NH3 emission and the physicochemical variables. The model was evaluated for 2012 NH3 emissions. The results indicate that, in comparison to other data sets, the model provides a lower global NH3 estimate by 58%, (NH3_STAT: 13.9 Tg N yr−1; Emission Database for Global Atmospheric Research: 33.0 Tg N yr−1). We also performed a region‐based analysis (United States, India, and China) using the NH3_STAT model. For the United States, our model produces an estimate that is a ~1.4 times higher in comparison to the Environmental Protection Agency. Meanwhile, the NH3_STAT estimate for India shows NH3 emissions between 0.8 and 1.4 times lower when compared to other data sets. A lower estimate is also seen for China, where the model estimates NH3 emissions 0.4 to 5 times lower than other data sets. The difference in the global estimates is attributed to the lower estimates in major agricultural countries like China and India. The statistical model captures the spatial distribution of global NH3 emissions by utilizing a simplified approach compared to other readily available data sets. Moreover, the NH3_STAT model provides an opportunity to predict future NH3 emissions in a changing world.}, number={3}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, publisher={American Geophysical Union (AGU)}, author={Aneja, Viney P. and Schlesinger, William H. and Li, Qi and Nahas, Alberth and Battye, William H.}, year={2020}, month={Feb} }
 @article{baker_battye_robarge_arya_aneja_2020, title={Modeling and measurements of ammonia from poultry operations: Their emissions, transport, and deposition in the Chesapeake Bay}, volume={706}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2019.1115290}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Baker, Jordan and Battye, William H. and Robarge, Wayne and Arya, S. Pal and Aneja, Viney P.}, year={2020}, month={Mar} }
 @article{baker_battye_robarge_arya_aneja_2020, title={Modeling and measurements of ammonia from poultry operations: Their emissions, transport, and deposition in the Chesapeake Bay}, volume={706}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85076257599&partnerID=MN8TOARS}, DOI={10.1016/j.scitotenv.2019.135290}, abstractNote={The goal of this study is to determine how much ammonia/nitrogen is being deposited to the Maryland Eastern Shore land and the Chesapeake Bay from poultry operations on Maryland's Eastern Shore. We simulated the fate of ammonia/nitrogen emitted (using emission factors from the U.S. EPA in conjunction with Carnegie-Mellon University) from 603 poultry facilities using the air quality model, AERMOD. The model domain was approximately 134 km by 230 km (and covers the full land area of Maryland's Eastern Shore), with a horizontal resolution of 2 km by 2 km. Ammonia concentration observations were made at 23 sites across Maryland's Eastern Shore during two periods (September and October 2017) in order to calibrate the model. An ammonia deposition velocity of 2.4 cm/sec was selected based on the sensitivity analysis of results for the simulation of a large poultry facility, and this value fell within the range of measurements reported in the scientific literature downwind of Concentrated Animal Feeding Operations (CAFOs). The ammonia deposition velocity of 2.4 cm/s leads to an estimated total annual ammonia deposition of 11,100 Megagrams/year (10,600 Mg/yr deposition to land, and 508 Mg/yr deposition to water (1 Mg = 1,000,000 g = 1.1023 US Tons)). In addition, model simulations indicate that ~72.4% of ammonia emissions from poultry animal feeding operations would be deposited within the modeling domain. However, this deposited ammonia/nitrogen may be transported through waterways from the land mass and ground water to the Chesapeake Bay. A comprehensive sensitivity analysis of the assumed ammonia deposition velocity (ranging from 0.15 to 3.0 cm/s) on estimated ammonia annual deposition is provided. Using the lower limit of an ammonia deposition velocity of 0.15 cm/s gives much smaller estimated total annual ammonia deposition of 2,040 Mg/yr (1,880 Mg/yr deposition to land and 163 Mg/yr deposition to water).}, journal={Science of the Total Environment}, author={Baker, Jordan and Battye, William H. and Robarge, Wayne and Arya, S. Pal and Aneja, Viney P.}, year={2020} }
 @article{pirhalla_heist_perry_hanna_mazzola_arya_aneja_2020, title={Urban wind field analysis from the Jack Rabbit II Special Sonic Anemometer Study}, volume={243}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85089852577&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2020.117871}, abstractNote={The Jack Rabbit II Special Sonic Anemometer Study (JRII-S), a field project designed to examine the flow and turbulence within a systematically arranged mock-urban environment constructed from CONEX shipping containers, is described in detail. The study involved the deployment of 35 sonic anemometers at multiple heights and locations, including a 32 m tall, unobstructed tower located about 115 m outside the building array to document the approach wind flow characteristics. The purpose of this work was to describe the experimental design, analyze the sonic data, and report observed wind flow patterns within the urban canopy in comparison to the approaching boundary layer flow. We show that the flow within the building array follows a tendency towards one of three generalized flow regimes displaying channeling over a wide range of wind speeds, directions, and stabilities. Two or more sonic anemometers positioned only a few meters apart can have vastly different flow patterns that are dictated by the building structures. Within the building array, turbulence values represented by normalized vertical velocity variance ( σw2 ) are at least two to three times greater than that in the approach flow. There is also little evidence that σw2 measured at various heights or locations within the JRII array is a strong function of stability type in contrast to the approach flow. The results reinforce how urban areas create complicated wind patterns, channeling effects, and localized turbulence that can impact the dispersion of an effluent release. These findings can be used to inform the development of improved wind flow algorithms to better characterize pollutant dispersion in fast-response models.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Pirhalla, Michael and Heist, David and Perry, Steven and Hanna, Steven and Mazzola, Thomas and Arya, S. Pal and Aneja, Viney}, year={2020}, month={Dec} }
 @misc{houlton_almaraz_aneja_austin_bai_cassman_compton_davidson_erisman_galloway_et al._2019, title={A World of Cobenefits: Solving the Global Nitrogen Challenge}, volume={7}, ISSN={["2328-4277"]}, url={https://doi.org/10.1029/2019EF001222}, DOI={10.1029/2019EF001222}, abstractNote={Nitrogen is a critical component of the economy, food security, and planetary health. Many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for (i) world hunger; (ii) soil, air, and water quality; (iii) climate change mitigation; and (iv) biodiversity conservation. Balancing the projected rise in agricultural nitrogen demands while achieving these 21st century ideals will require policies to coordinate solutions among technologies, consumer choice, and socioeconomic transformation.}, number={8}, journal={EARTHS FUTURE}, publisher={American Geophysical Union (AGU)}, author={Houlton, Benjamin Z. and Almaraz, Maya and Aneja, Viney and Austin, Amy T. and Bai, Edith and Cassman, Kenneth G. and Compton, Jana E. and Davidson, Eric A. and Erisman, Jan Willem and Galloway, James N. and et al.}, year={2019}, month={Aug}, pages={865–872} }
 @article{aneja_schlesinger_li_nahas_battye_2019, title={Characterization of atmospheric nitrous oxide emissions from global agricultural soils}, volume={1}, ISBN={2523-3971}, url={https://doi.org/10.1007/s42452-019-1688-5}, DOI={10.1007/s42452-019-1688-5}, abstractNote={Nitrous oxide (N2O) is a potent greenhouse gas with an atmospheric lifetime of ~ 114 years. Agriculture activities are the main sources for N2O emission into the atmosphere by human activities. Global N2O emissions into the atmosphere are projected to increase in the coming years as demand for food, fibre and energy increases owing to increasing global population. Here, a statistical model (N2O_STAT) is developed for characterizing atmospheric N2O emissions from agricultural sources. We obtained N2O emissions and physicochemical variables (i.e. air temperature, soil temperature, soil moisture, soil pH, and N input to the soil) from published journal articles since 2000. A statistical model was developed by expressing a multiple linear regression equation between N2O emission and the physicochemical variables. The model was evaluated for 2012 N2O emissions. Results of the model are compared with other global and regional N2O models (e.g. EDGAR, EPA/USGS, and FAOSTAT). In comparison with other data sets, the model generates a lower global N2O estimate by 9–20% (N2O_STAT: 3.75 Tg N yr−1; EDGAR: 4.49 Tg N yr−1; FAO: 4.07 Tg N yr−1), but is ~ 25% higher when compared to Bouwman et al. (Glob Biogeochem Cycles 16:1–9. https://doi.org/10.1029/2001gb001812 , 2002) (2.80 Tg N yr−1). We also performed a region-based analysis (USA, India, and China) using the N2O_STAT model. For the USA, our model produces an estimate that ranges from − 13 to + 32% in comparison with other published data sets. Meanwhile, the N2O_STAT model estimate for India shows N2O emissions between − 56 and + 14% when compared to other data sets. A much lower estimate is seen for China, where the model estimates N2O emissions 38–177% lower than other data sets. The N2O_STAT model provides an opportunity to predict future N2O emissions in a changing world.}, number={12}, journal={SN APPLIED SCIENCES}, publisher={Springer Science and Business Media LLC}, author={Aneja, Viney P. and Schlesinger, William H. and Li, Qi and Nahas, Alberth and Battye, William H.}, year={2019}, month={Dec} }
 @article{battye_bray_aneja_tong_lee_tang_2019, title={Evaluating Ammonia (NH3) Predictions in the NOAA NAQFC for Eastern North Carolina Using Ground Level and Satellite Measurements}, volume={124}, ISSN={["2169-8996"]}, url={https://doi.org/10.1029/2018JD029990}, DOI={10.1029/2018JD029990}, abstractNote={Ammonia (NH3) in the atmosphere contributes to the formation of airborne fine particulate matter (PM2.5), which is associated with adverse human health effects. The emission, transport, reactions, and deposition of NH3 in the atmosphere are modeled using the Community Multiscale Air Quality (CMAQ) model, within the U.S. National Air Quality Forecast Capability (NAQFC). The purpose of this current work is to evaluate the capability of the NAQFC CMAQ model and to identify potential improvements to NH3 emissions estimates and prediction methods. This study focuses on CMAQ predictions of atmospheric NH3 in North Carolina, including a region with intensive animal production and enhanced NH3 emissions. The CMAQ model is run for July 2011 using a version of the 2011 National Emissions Inventory in which agricultural NH3 emissions were adjusted to reflect the lower end of the range of estimates from the current process‐based emissions model. The NAQFC CMAQ model overpredicted atmospheric NH3 at a continuous monitor in Clinton, NC, within the region of intensive animal production. The average concentration measured by the monitor was 6.6 ppbv, while the average predicted by the model was 10.5 ppbv, a 60% overprediction. Outside of the region of intensive animal production, both measured and modeled NH3 concentrations were low, 1.3 ppbv or less. The model underpredicted wet deposition of NH4+ and dry deposition of NH3. It is believed that the overestimation of NH3 at Clinton is attributable at least in part to the underestimation of wet and dry deposition in North Carolina.}, number={14}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, publisher={American Geophysical Union (AGU)}, author={Battye, William H. and Bray, Casey D. and Aneja, Viney P. and Tong, Daniel and Lee, Pius and Tang, Youhua}, year={2019}, month={Jul}, pages={8242–8259} }
 @article{bray_battye_aneja_2019, title={The role of biomass burning agricultural emissions in the Indo-Gangetic Plains on the air quality in New Delhi, India}, volume={218}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85072624596&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2019.116983}, abstractNote={Agricultural residue burning in the Indo-Gangetic Plains (IGP) releases large amounts of reactive nitrogen, among other pollutants, into the atmosphere each year. This study focuses on rice paddy residue burning and wheat residue burning during October–November and April–May, respectively, in 2016 and 2017. Emissions of reactive nitrogen species (ammonia (NH3), nitrous oxide (N2O) and oxides of nitrogen (NOx = NO + NO2)) were estimated for the study period using a suite of satellite products from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the National Aeronautics and Space Administration (NASA) Aqua and Terra satellites. Emissions were compared against ambient concentrations of fine particulate matter (PM2.5) in New Delhi, India, to help determine the impact that these agricultural burns have on PM2.5, which is known to have numerous health and environmental impacts associated with prolonged exposure to elevated concentrations. Daily average measured concentrations of PM2.5 in New Delhi range from 22.43 μg m−3 to 718.94 μg m−3 (average 127.15 μg m−3 ± 95.23 μg m−3), with the daily average PM2.5 concentration exceeding the national ambient air quality standard of 60 μg m−3 approximately 75% of the time. Concentrations of PM2.5 were found to peak during October–November, which corresponds with rice paddy residue burning in the IGP. In addition to this, statistical regression models were created to predict average daily PM2.5 concentrations in New Delhi, India, based on emissions of NH3 and organic carbon (OC) in the IGP as well as meteorological conditions. The regression model predicted ambient PM2.5 concentrations ranging from 35 to 719 μg m−3. The average modeled concentrations of PM2.5 in New Delhi, India, were 111 μg m−3 (standard deviation: ± 23 μg m−3) during April/May and 207 ± 87 μg m−3 during October/November. Both regression models (for wheat residue burning and for rice paddy residue burning) were comparable to the average observations (normalized mean bias less than 0.1%).}, journal={ATMOSPHERIC ENVIRONMENT}, author={Bray, Casey D. and Battye, William H. and Aneja, Viney P.}, year={2019}, month={Dec} }
 @article{bray_battye_aneja_tong_lee_tang_2018, title={Ammonia emissions from biomass burning in the continental United States}, volume={187}, ISSN={1352-2310}, url={http://dx.doi.org/10.1016/J.ATMOSENV.2018.05.052}, DOI={10.1016/J.ATMOSENV.2018.05.052}, abstractNote={This study quantifies ammonia (NH3) emissions from biomass burning from 2005 to 2015 across the continental US (CONUS) and compares emissions from biomass burning with the US Environmental Protection Agency (EPA) National Emissions Inventory (NEI), the Fire Inventory from the National Center for Atmospheric Research (FINN) and the Global Fire Emissions Database (GFED). A statistical regression model was developed in order to predict NH3 emissions from biomass burning using a combination of fire properties and meteorological data. Satellite data were used to evaluate the annual fire strength and frequency as well as to calculate the total NH3 emissions across the CONUS. The results of this study showed the total fire number has decreased, while the total yearly burn area and the average fire radiative power has increased. The average annual NH3 emissions from biomass burning from this study, on a national scale, were approximately 5.4e8 ± 3.3e8 kg year−1. When comparing the results of this study with other emission inventories, it was found that ammonia emissions estimated by the NEI were approximately a factor of 1.3 lower than what was calculated in this study and a factor of 1.1 lower than what was modeled using the statistical regression model for 2010–2014. The calculated NH3 emissions from biomass burning were a factor of 5.9 and a factor of 13.1 higher than the emissions from FINN and the GFED, respectively. The modeled NH3 emissions from biomass burning were a factor of 5.0 and a factor of 11.1 higher than the emissions from FINN and the GFED, respectively. As the climate continues to change, the pattern (frequency, intensity and magnitude) of fires across the US will also change, leading to changes in NH3 emissions. The statistical regression model developed in this study will allow prediction of NH3 emissions associated with climate change.}, journal={Atmospheric Environment}, publisher={Elsevier BV}, author={Bray, Casey D. and Battye, William and Aneja, Viney P. and Tong, Daniel Q. and Lee, Pius and Tang, Youhua}, year={2018}, month={Aug}, pages={50–61} }
 @article{uttamang_aneja_hanna_2018, title={Assessment of gaseous criteria pollutants in the Bangkok Metropolitan Region, Thailand}, volume={18}, ISSN={["1680-7324"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85052819254&partnerID=MN8TOARS}, DOI={10.5194/acp-18-12581-2018}, abstractNote={Abstract. The analysis of gaseous criteria pollutants in the Bangkok
Metropolitan Region (BMR), Thailand, from 2010 to 2014 reveals that while the
hourly concentrations of CO, SO2 and NO2 were mostly
within the National Ambient Air Quality Standards (NAAQs) of Thailand, the
hourly concentrations of O3 frequently exceeded the standard. The
results reveal that the problem of high O3 concentration
continuously persisted in this area. The O3 photolytic rate
constant (j1) for BMR calculated based on assuming a photostationary
state ranged from 0.008 to 0.013 s−1, which is similar to the
calculated j1 using the NCAR TUV model (0.021±0.0024 s−1).
Interconversion between O3, NO and NO2 indicates that
crossover points between the species occur when the concentration of
NOx (= NO + NO2) is ∼60 ppb. Under a
low-NOx regime ([NOx] < 60 ppb),
O3 is the dominant species, while, under a
high-NOx regime ([NOx]
> 60 ppb), NO dominates. Linear regression analysis between the
concentrations of Ox (= O3 + NO2)
and NOx provides the role of local and regional
contributions to Ox. During O3 episodes
([O3]hourly > 100 ppb), the values of the
local and regional contributions were nearly double of those during
non-episodes. Ratio analysis suggests that the major contributors of primary
pollutants over BMR are mobile sources. The air quality index (AQI) for BMR
was predominantly good to moderate; however, unhealthy O3
categories were observed during episode conditions in the region.
}, number={16}, journal={ATMOSPHERIC CHEMISTRY AND PHYSICS}, author={Uttamang, Pornpan and Aneja, Viney P. and Hanna, Adel F.}, year={2018}, month={Aug}, pages={12581–12593} }
 @article{nagar_singh_sharma_kumar_aneja_george_agarwal_shukla_2017, title={Characterization of PM2.5 in Delhi: role and impact of secondary aerosol, burning of biomass, and municipal solid waste and crustal matter}, volume={24}, ISSN={["1614-7499"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85029576312&partnerID=MN8TOARS}, DOI={10.1007/s11356-017-0171-3}, number={32}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Nagar, Pavan K. and Singh, Dhirendra and Sharma, Mukesh and Kumar, Anil and Aneja, Viney P. and George, Mohan P. and Agarwal, Nigam and Shukla, Sheo P.}, year={2017}, month={Nov}, pages={25179–25189} }
 @article{bray_battye_uttamang_pillai_aneja_2017, title={Characterization of Particulate Matter (PM2.5 and PM10) Relating to a Coal Power Plant in the Boroughs of Springdale and Cheswick, PA}, volume={8}, ISSN={["2073-4433"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85030543881&partnerID=MN8TOARS}, DOI={10.3390/atmos8100186}, abstractNote={Ambient concentrations of both fine particulate matter (PM2.5) and particulate matter with an aerodynamic diameter less than 10 micron (PM10) were measured from 10 June 2015 to 13 July 2015 at three locations surrounding the Cheswick Power Plant, which is located between the boroughs of Springdale and Cheswick, Pennsylvania. The average concentrations of PM10 observed during the periods were 20.5 ± 10.2 μg m−3 (Station 1), 16.1 ± 4.9 μg m−3 (Station 2) and 16.5 ± 7.1 μg m−3 (Station 3). The average concentrations of PM2.5 observed at the stations were 9.1 ± 5.1 μg m−3 (Station 1), 0.2 ± 0.4 μg m−3 (Station 2) and 11.6 ± 4.8 μg m−3 (Station 3). In addition, concentrations of PM2.5 measured by four Pennsylvania Department of Environmental Protection air quality monitors (all within a radius of 40 miles) were also analyzed. The observed average concentrations at these sites were 12.7 ± 6.9 μg m−3 (Beaver Falls), 11.2 ± 4.7 μg m−3 (Florence), 12.2 ± 5.3 μg m−3 (Greensburg) and 12.2 ± 5.5 μg m−3 (Washington). Elemental analysis for samples (blank – corrected) revealed the presence of metals that are present in coal (i.e., antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel and selenium).}, number={10}, journal={ATMOSPHERE}, author={Bray, Casey D. and Battye, William and Uttamang, Pornpan and Pillai, Priya and Aneja, Viney P.}, year={2017}, month={Oct} }
 @article{rudek_aneja_abrol_2017, title={Concepts for Considerations in the Design of an Indian Integrated Nitrogen Assessment}, ISBN={["978-0-12-811836-8"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054423239&partnerID=MN8TOARS}, DOI={10.1016/b978-0-12-811836-8.00003-3}, abstractNote={The ready availability of industrially fixed reactive nitrogen (Nr) has resulted in a substantial accumulation of Nr in the biosphere. Proper management of Nr is necessary to minimize its negative consequences, while allowing maximization to its positive benefits. An integrated Nr assessment which has not yet been undertaken for India, would be prudent given the future population projections. Basic concepts of an integrated scientific assessment are discussed and two previous integrated Nr assessments (USA and Europe) are compared and contrasted to provide examples from which to draw upon for the design and implementation of an India integrated Nr assessment.}, journal={INDIAN NITROGEN ASSESSMENT: SOURCES OF REACTIVE NITROGEN, ENVIRONMENTAL AND CLIMATE EFFECTS, MANAGEMENT OPTIONS, AND POLICIES}, author={Rudek, J. and Aneja, V. P. and Abrol, Y. P.}, year={2017}, pages={29–43} }
 @article{bray_battye_aneja_tong_lee_tang_nowak_2017, title={Evaluating ammonia (NH3) predictions in the NOAA National Air Quality Forecast Capability (NAQFC) using in-situ aircraft and satellite measurements from the CalNex2010 campaign}, volume={163}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85019951530&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2017.05.032}, abstractNote={Atmospheric ammonia (NH3) is not only a major precursor gas for fine particulate matter (PM2.5), but it also negatively impacts the environment through eutrophication and acidification. As the need for agriculture, the largest contributing source of NH3, increases, NH3 emissions will also increase. Therefore, it is crucial to accurately predict ammonia concentrations. The objective of this study is to determine how well the U.S. National Oceanic and Atmospheric Administration (NOAA) National Air Quality Forecast Capability (NAQFC) system predicts ammonia concentrations using their Community Multiscale Air Quality (CMAQ) model (v4.6). Model predictions of atmospheric ammonia are compared against measurements taken during the NOAA California Nexus (CalNex) field campaign that took place between May and July of 2010. Additionally, the model predictions were also compared against ammonia measurements obtained from the Tropospheric Emission Spectrometer (TES) on the Aura satellite. The results of this study showed that the CMAQ model tended to under predict concentrations of NH3. When comparing the CMAQ model with the CalNex measurements, the model under predicted NH3 by a factor of 2.4 (NMB = −58%). However, the ratio of the median measured NH3 concentration to the median of the modeled NH3 concentration was 0.8. When compared with the TES measurements, the model under predicted concentrations of NH3 by a factor of 4.5 (NMB = −77%), with a ratio of the median retrieved NH3 concentration to the median of the modeled NH3 concentration of 3.1. Because the model was the least accurate over agricultural regions, it is likely that the major source of error lies within the agricultural emissions in the National Emissions Inventory. In addition to this, the lack of the use of bidirectional exchange of NH3 in the model could also contribute to the observed bias.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Bray, Casey D. and Battye, William and Aneja, Viney P. and Tong, Daniel and Lee, Pius and Tang, Youhua and Nowak, John B.}, year={2017}, month={Aug}, pages={65–76} }
 @article{battye_aneja_schlesinger_2017, title={Is nitrogen the next carbon?}, volume={5}, ISSN={["2328-4277"]}, url={https://doi.org/10.1002/2017EF000592}, DOI={10.1002/2017ef000592}, abstractNote={Just as carbon fueled the Industrial Revolution, nitrogen has fueled an Agricultural Revolution. The use of synthetic nitrogen fertilizers and the cultivation of nitrogen‐fixing crops both expanded exponentially during the last century, with most of the increase occurring after 1960. As a result, the current flux of reactive, or fixed, nitrogen compounds to the biosphere due to human activities is roughly equivalent to the total flux of fixed nitrogen from all natural sources, both on land masses and in the world's oceans. Natural fluxes of fixed nitrogen are subject to very large uncertainties, but anthropogenic production of reactive nitrogen has increased almost fivefold in the last 60 years, and this rapid increase in anthropogenic fixed nitrogen has removed any uncertainty on the relative importance of anthropogenic fluxes to the natural budget. The increased use of nitrogen has been critical for increased crop yields and protein production needed to keep pace with the growing world population. However, similar to carbon, the release of fixed nitrogen into the natural environment is linked to adverse consequences at local, regional, and global scales. Anthropogenic contributions of fixed nitrogen continue to grow relative to the natural budget, with uncertain consequences.}, number={9}, journal={EARTHS FUTURE}, publisher={Wiley-Blackwell}, author={Battye, William and Aneja, Viney P. and Schlesinger, William H.}, year={2017}, month={Sep}, pages={894–904} }
 @article{aneja_pillai_isherwood_morgan_aneja_2017, title={Particulate matter pollution in the coal-producing regions of the Appalachian Mountains: Integrated ground-based measurements and satellite analysis}, volume={67}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85013124200&partnerID=MN8TOARS}, DOI={10.1080/10962247.2016.1245686}, abstractNote={ABSTRACT This study integrates the relationship between measured surface concentrations of particulate matter 10 μm or less in diameter (PM10), satellite-derived aerosol optical depth (AOD), and meteorology in Roda, Virginia, during 2008. A multiple regression model was developed to predict the concentrations of particles 2.5 μm or less in diameter (PM2.5) at an additional location in the Appalachia region, Bristol, TN. The model was developed by combining AOD retrievals from Moderate Resolution Imaging Spectro-radiometer (MODIS) sensor on board the EOS Terra and Aqua Satellites with the surface meteorological observations. The multiple regression model predicted PM2.5 (r2 = 0.62), and the two-variable (AOD-PM2.5) model predicted PM2.5 (r2 = 0.4). The developed model was validated using particulate matter recordings and meteorology observations from another location in the Appalachia region, Hazard, Kentucky. The model was extrapolated to the Roda, VA, sampling site to predict PM2.5 mass concentrations. We used 10 km x 10 km resolution MODIS 550 nm AOD to predict ground level PM2.5. For the relevant period in 2008, in Roda, VA, the predicted PM2.5 mass concentration is 9.11 ± 5.16 μg m-3 (mean ± 1SD). Implications: This is the first study that couples ground-based Particulate Matter measurements with satellite retrievals to predict surface air pollution at Roda, Virginia. Roda is representative of the Appalachian communities that are commonly located in narrow valleys, or “hollows,” where homes are placed directly along the roads in a region of active mountaintop mining operations. Our study suggests that proximity to heavy coal truck traffic subjects these communities to chronic exposure to coal dust and leads us to conclude that there is an urgent need for new regulations to address the primary sources of this particulate matter.}, number={4}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Pillai, Priya R. and Isherwood, Aaron and Morgan, Peter and Aneja, Saurabh P.}, year={2017}, pages={421–430} }
 @book{abrol_adhya_aneja_raghuram_pathak_kulshrestha_sharma_singh_2017, title={The Indian Nitrogen Assessment: Sources of Reactive Nitrogen, Environmental and Climate Effects, Management Options, and Policies}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054449431&partnerID=MN8TOARS}, journal={The Indian Nitrogen Assessment: Sources of Reactive Nitrogen, Environmental and Climate Effects, Management Options, and Policies}, author={Abrol, Y.P. and Adhya, T.K. and Aneja, V.P. and Raghuram, N. and Pathak, H. and Kulshrestha, U. and Sharma, C. and Singh, B.}, year={2017}, pages={1–538} }
 @article{abrol_adhya_aneja_raghuram_pathak_kulshrestha_sharma_singh_2017, title={The Indian nitrogen assessment sources of reactive nitrogen, environmental and climate effects, management options, and policies preface}, journal={Indian Nitrogen Assessment: Sources of Reactive Nitrogen, Environmental and Climate Effects, Management Options, and Policies}, author={Abrol, Y. P. and Adhya, T. K. and Aneja, V. P. and Raghuram, N. and Pathak, H. and Kulshrestha, U. and Sharma, C. and Singh, B.}, year={2017}, pages={XXVII-} }
 @article{shukla_srivastava_banerjee_aneja_2017, title={Trend and variability of atmospheric ozone over middle Indo-Gangetic Plain: impacts of seasonality and precursor gases}, volume={24}, ISSN={0944-1344 1614-7499}, url={http://dx.doi.org/10.1007/S11356-016-7738-2}, DOI={10.1007/S11356-016-7738-2}, number={1}, journal={Environmental Science and Pollution Research}, publisher={Springer Science and Business Media LLC}, author={Shukla, K. and Srivastava, Prashant K. and Banerjee, T. and Aneja, Viney P.}, year={2017}, month={Jan}, pages={164–179} }
 @article{battye_bray_aneja_tong_lee_tang_2016, title={Evaluating ammonia (NH3) predictions in the NOAA National Air Quality Forecast Capability (NAQFC) using in situ aircraft, ground-level, and satellite measurements from the DISCOVER-AQ Colorado campaign}, volume={140}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84973922839&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2016.06.021}, abstractNote={The U.S. National Oceanic and Atmospheric Administration (NOAA) is responsible for forecasting elevated levels of air pollution within the National Air Quality Forecast Capability (NAQFC). The current research uses measurements gathered in the DISCOVER-AQ Colorado field campaign and the concurrent Front Range Air Pollution and Photochemistry Experiment (FRAPPE) to test performance of the NAQFC CMAQ modeling framework for predicting NH3. The DISCOVER-AQ and FRAPPE field campaigns were carried out in July and August 2014 in Northeast Colorado. Model predictions are compared with measurements of NH3 gas concentrations and the NH4+ component of fine particulate matter concentrations measured directly by the aircraft in flight. We also compare CMAQ predictions with NH3 measurements from ground-based monitors within the DISCOVER-AQ Colorado geographic domain, and from the Tropospheric Emission Spectrometer (TES) on the Aura satellite. In situ aircraft measurements carried out in July and August of 2014 suggest that the NAQFC CMAQ model underestimated the NH3 concentration in Northeastern Colorado by a factor of ∼2.7 (NMB = −63%). Ground-level monitors also produced a similar result. Average satellite-retrieved NH3 levels also exceeded model predictions by a factor of 1.5–4.2 (NMB = −33 to −76%). The underestimation of NH3 was not accompanied by an underestimation of particulate NH4+, which is further controlled by factors including acid availability, removal rate, and gas-particle partition. The average measured concentration of NH4+ was close to the average predication (NMB = +18%). Seasonal patterns measured at an AMoN site in the region suggest that the underestimation of NH3 is not due to the seasonal allocation of emissions, but to the overall annual emissions estimate. The underestimation of NH3 varied across the study domain, with the largest differences occurring in a region of intensive agriculture near Greeley, Colorado, and in the vicinity of Denver. The NAQFC modeling framework did not include a recently developed bidirectional flux algorithm for NH3, which has shown to considerably improve NH3 modeling in agricultural regions. The bidirectional flux algorithm, however, is not expected to obtain the magnitude of this increase sufficient to overcome the underestimation of NH3 found in this study. Our results suggest that further improvement of the emission inventories and modeling approaches are required to reduce the bias in NAQFC NH3 modeling predictions.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Battye, William H. and Bray, Casey D. and Aneja, Viney P. and Tong, Daniel and Lee, Pius and Tang, Youhua}, year={2016}, month={Sep}, pages={342–351} }
 @article{jiang_ajmeri_chirkova_doyle_singh_2016, place={United States}, title={Expressing and Reasoning about Conflicting Norms in Cybersecurity: Poster}, url={https://publons.com/publon/21294386/}, DOI={10.1145/2898375.2898395}, abstractNote={Secure collaboration requires the collaborating parties to apply the right policies for their interaction. We adopt a notion of conditional, directed norms as a way to capture the standards of correctness for a collaboration. How can we handle conflicting norms? We describe an approach based on knowledge of what norm dominates what norm in what situation. Our approach adapts answer-set programming to compute stable sets of norms with respect to their computed conflicts and dominance. It assesses agent compliance with respect to those stable sets. We demonstrate our approach on a healthcare scenario.}, journal={SYMPOSIUM AND BOOTCAMP ON THE SCIENCE OF SECURITY}, publisher={ACM Press}, author={Jiang, Jiaming and Ajmeri, Nirav and Chirkova, Rada Y. and Doyle, Jon and Singh, Munindar P.}, year={2016}, pages={63–64} }
 @article{mikel_aneja_2016, title={Measurements and Analysis of Polycyclic Aromatic Hydrocarbons near a Major Interstate}, volume={7}, ISSN={["2073-4433"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84994875690&partnerID=MN8TOARS}, DOI={10.3390/atmos7100131}, abstractNote={Polycyclic aromatic hydrocarbons (PAHs) were measured near Interstate 40, just east of Research Triangle Park, North Carolina, USA. The goals of this project were to ascertain whether a sufficient quantity of PAHs could be collected using low flow (16.7 L/minute) over 8-h periods and if so, do investigate how the PAHs correlate to local sources, atmospheric pollutants and meteorology. The 8-h integrated samples were collected on 20 sampling days over a two month period during fall 2014. The samples were collected using low flow (BGI Incorporated PQ200) fine particulate samplers analyzed using gas chromatography-mass spectrometry (GC-MS). Temporal distributions of the PAHs (average mean 9.2 nanogram/cubic meter ±9.0 std) were compared to traffic count, and meteorological and pollutant data collected at the near roadway station. Using the meteorological data (i.e., wind speed and direction vector data), wind roses were created illustrating the local sources of the PAHs. In terms of correlation to atmospheric oxidants, (i.e., ozone, nitrogen dioxide and nitric oxide) wind rose analysis illustrated the morning hours which were predominantly southern winds, while the afternoon hours illustrated southerly and easterly winds, which suggests that the automobile traffic is the main source of PAHs. The nighttime hours wind rose shows winds from the northerly and easterly direction, which are predominantly from the RDU International Airport. Since the wind direction vectors illustrated that the afternoon hours (i.e., 12 p.m. to 8 p.m.) were from the interstate, comparisons were performed on the samples collected in this time period for both the traffic and pollutant data. The comparison of the traffic data showed a correlation with the number of vehicles (>60 feet i.e., heavy duty diesel engine vehicles). In addition, with the ozone, nitrogen dioxide and nitric oxide) there is a significant linear correlation between the sum of the measured PAHs with nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) with the R2 values being 0.1, 0.04 and 0.07 respectively. An analysis of variance (ANOVA) statistical regression was performed on the pollutant data versus the measured sum of the PAHs. With the alpha set at 0.05, (α = 0.05) the p-values for O3, NO2 and NO were 0.00613, 0.000496 and 0.000264, respectively, which are significant. In addition, the PAH concentration found in this study compare favorably to other published studies (0.1 to 193.6 ng/m3) both nationally and internationally.}, number={10}, journal={ATMOSPHERE}, author={Mikel, Dennis K. and Aneja, Viney P.}, year={2016}, month={Oct} }
 @article{aneja_schlesinger_aneja_2015, title={Effects of intensively managed agriculture on the atmospheric environment}, volume={65}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937605446&partnerID=MN8TOARS}, number={June}, journal={EM: Air and Waste Management Association's Magazine for Environmental Managers}, author={Aneja, V.P. and Schlesinger, W.H. and Aneja, S.P.}, year={2015}, pages={24–30} }
 @article{rasheed_aneja_aiyyer_rafique_2015, title={Measurement and Analysis of Fine Particulate Matter (PM2.5) in Urban Areas of Pakistan}, volume={15}, ISSN={["2071-1409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84925941359&partnerID=MN8TOARS}, DOI={10.4209/aaqr.2014.10.0269}, abstractNote={In order to assess the extent of air quality within the major urban environments in Pakistan, PM_(2.5) pollutant has been analyzed during the period 2007-2011 in Islamabad; and 2007 to 2008 in Lahore, Peshawar and Quetta (high elevation, 1680 m MSL). Seasonal and diurnal variations of PM_(2.5) mass concentration formation and accumulation within these areas have been analyzed. Air quality monitoring data and meteorological data (both QA/QCed) were obtained from Federal and Provincial Pakistan Environmental Protection Agencies. In Islamabad, the annual average PM_(2.5) mass concentrations were 81.1 ± 48.4 μg/m^3, 93.0 ± 49.9 μg/m^3, 47.8 ± 33.2 μg/m^3, 79.0 ± 49.2 μg/m^3, and 66.1 ± 52.1 μg/m^3 during 2007 to 2011 respectively. Comparison of the four cities during summer 2007 to spring 2008 shows that all the four cities had PM_(2.5) concentration exceeding the Pakistan National Environmental Quality Standards (annual average concentration of 25 μg/m^3; and 24 hourly average concentration of 40 μg/m^3) for ambient air. During the same time period, the highest seasonal PM_(2.5) mass concentrations for Islamabad were observed as 98.5 μg/m^3 during spring 2008; 150.4 ± 87.9 μg/m^3; 104.1 ± 51.1 μg/m^3 and 72.7 ± 55.2 μg/m^3 for Lahore, Peshawar, and Quetta during fall 2007, respectively. Wind speed and temperature have a negative correlation with the mass concentration of PM_(2.5). Diurnal profile for all the cities suggests an association of PM_(2.5) with vehicular traffic. Back trajectory analysis conducted using the NOAA HYSPLIT model indicates that air trajectories, during high pollution episodes, influencing the urban regions commonly originate from either western India, especially in summer as part of the prevailing monsoon circulation; or are located in eastern Afghanistan. The source areas in Western India i.e., states of Gujarat, Rajasthan and Punjab have high concentration of industrial activities and crop residue burning, and are likely sources of enhanced PM_(2.5) concentrations, in addition to the local sources.}, number={2}, journal={AEROSOL AND AIR QUALITY RESEARCH}, author={Rasheed, Anjum and Aneja, Viney P. and Aiyyer, Anantha and Rafique, Uzaira}, year={2015}, month={Apr}, pages={426–439} }
 @inproceedings{mikel_aneja_2015, title={Measurement of polycyclic aromatic hydrocarbons near a major roadway}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84983063653&partnerID=MN8TOARS}, booktitle={Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA}, author={Mikel, D. and Aneja, V.P.}, year={2015}, pages={1418–1426} }
 @article{yu_luo_pryor_pillai_lee_ortega_schwab_hallar_leaitch_aneja_et al._2015, title={Spring and summer contrast in new particle formation over nine forest areas in North America}, volume={15}, ISSN={["1680-7324"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84946816099&partnerID=MN8TOARS}, DOI={10.5194/acp-15-13993-2015}, abstractNote={Abstract. Recent laboratory chamber studies indicate a significant role for highly oxidized low-volatility organics in new particle formation (NPF), but the actual role of these highly oxidized low-volatility organics in atmospheric NPF remains uncertain. Here, particle size distributions (PSDs) measured in nine forest areas in North America are used to characterize the occurrence and intensity of NPF and to evaluate model simulations using an empirical formulation in which formation rate is a function of the concentrations of sulfuric acid and low-volatility organics from alpha-pinene oxidation (Nucl-Org), and using an ion-mediated nucleation mechanism (excluding organics) (Nucl-IMN). On average, NPF occurred on ~ 70 % of days during March for the four forest sites with springtime PSD measurements, while NPF occurred on only ~ 10 % of days in July for all nine forest sites. Both Nucl-Org and Nucl-IMN schemes capture the observed high frequency of NPF in spring, but the Nucl-Org scheme significantly overpredicts while the Nucl-IMN scheme slightly underpredicts NPF and particle number concentrations in summer. Statistical analyses of observed and simulated ultrafine particle number concentrations and frequency of NPF events indicate that the scheme without organics agrees better overall with observations. The two schemes predict quite different nucleation rates (including their spatial patterns), concentrations of cloud condensation nuclei, and aerosol first indirect radiative forcing in North America, highlighting the need to reduce NPF uncertainties in regional and global earth system models.}, number={24}, journal={ATMOSPHERIC CHEMISTRY AND PHYSICS}, author={Yu, F. and Luo, G. and Pryor, S. C. and Pillai, P. R. and Lee, S. H. and Ortega, J. and Schwab, J. J. and Hallar, A. G. and Leaitch, W. R. and Aneja, V. P. and et al.}, year={2015}, pages={13993–14003} }
 @inbook{gore_cooter_dennis_pleim_aneja_2014, title={Ammonia emissions in the US: Assessing the role of bi-directional ammonia transport using the community multi-scale air quality (CMAQ) model}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84948122259&partnerID=MN8TOARS}, DOI={10.1007/978-94-007-7939-6_4}, booktitle={Nitrogen Deposition, Critical Loads and Biodiversity: Proceedings of the International Nitrogen Initiative Workshop, Linking Experts of the Convention on Long-Range Transboundary Air Pollution and the Convention on Biological Diversity}, author={Gore, M.L. and Cooter, E.J. and Dennis, R.L. and Pleim, J.E. and Aneja, V.P.}, year={2014}, pages={31–38} }
 @article{rumsey_aneja_lonneman_2014, title={Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding operation}, volume={94}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84901479235&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2014.05.041}, abstractNote={Reduced sulfur compounds (RSCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern, as a result of changes in livestock production methods. RSC emissions were determined from a swine CAFO in North Carolina. RSC measurements were made over a period of ≈1 week from both the barn and lagoon during each of the four seasonal periods from June 2007 to April 2008. During sampling, meteorological and other environmental parameters were measured continuously. Seasonal hydrogen sulfide (H2S) barn concentrations ranged from 72 to 631 ppb. Seasonal dimethyl sulfide (DMS; CH3SCH3) and dimethyl disulfide (DMDS; CH3S2CH3) concentrations were 2–3 orders of magnitude lower, ranging from 0.18 to 0.89 ppb and 0.47 to 1.02 ppb, respectively. The overall average barn emission rate was 3.3 g day−1 AU−1 (AU (animal unit) = 500 kg of live animal weight) for H2S, which was approximately two orders of magnitude higher than the DMS and DMDS overall average emissions rates, determined as 0.017 g day−1 AU−1 and 0.036 g day−1 AU−1, respectively. The overall average lagoon flux was 1.33 μg m−2 min−1 for H2S, which was approximately an order of magnitude higher than the overall average DMS (0.12 μg m−2 min−1) and DMDS (0.09 μg m−2 min−1) lagoon fluxes. The overall average lagoon emission for H2S (0.038 g day−1 AU−1) was also approximately an order of magnitude higher than the overall average DMS (0.0034 g day−1 AU−1) and DMDS (0.0028 g day−1 AU−1) emissions. H2S, DMS and DMDS have offensive odors and low odor thresholds. Over all four sampling seasons, 77% of 15 min averaged H2S barn concentrations were an order of magnitude above the average odor threshold. During these sampling periods, however, DMS and DMDS concentrations did not exceed their odor thresholds. The overall average barn and lagoon emissions from this study were used to help estimate barn, lagoon and total (barn + lagoon) RSC emissions from swine CAFOs in North Carolina. Total (barn + lagoon) H2S emissions from swine CAFOs in North Carolina were estimated to be 1.22*106 kg yr−1. The barns had significantly higher H2S emissions than the lagoons, contributing ≈98% of total North Carolina H2S swine CAFO emissions. Total (barn + lagoon) emissions for DMS and DMDS were 1–2 orders of magnitude lower, with barns contributing ≈86% and ≈93% of total emissions, respectively. H2S swine CAFO emissions were estimated to contribute ≈18% of North Carolina H2S emissions.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Rumsey, Ian C. and Aneja, Viney P. and Lonneman, William A.}, year={2014}, month={Sep}, pages={458–466} }
 @article{rumsey_aneja_2014, title={Measurement and Modeling of Hydrogen Sulfide Lagoon Emissions from a Swine Concentrated Animal Feeding Operation}, volume={48}, ISSN={["1520-5851"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84893569333&partnerID=MN8TOARS}, DOI={10.1021/es403716w}, abstractNote={Hydrogen sulfide (H2S) emissions were determined from an anaerobic lagoon at a swine concentrated animal feeding operation (CAFO) in North Carolina. Measurements of H2S were made continuously from an anaerobic lagoon using a dynamic flow-through chamber for ∼ 1 week during each of the four seasonal periods from June 2007 through April 2008. H2S lagoon fluxes were highest in the summer with a flux of 3.81 ± 3.24 μg m(-2) min(-1) and lowest in the winter with a flux of 0.08 ± 0.09 μg m(-2) min(-1). An air-manure interface (A-MI) mass transfer model was developed to predict H2S manure emissions. The accuracy of the A-MI mass transfer model in predicting H2S manure emissions was comprehensively evaluated by comparing the model predicted emissions to the continuously measured lagoon emissions using data from all four seasonal periods. In comparison to this measurement data, the A-MI mass transfer model performed well in predicting H2S fluxes with a slope of 1.13 and an r(2) value of 0.60, and a mean bias value of 0.655 μg m(-2) min(-1). The A-MI mass transfer model also performed fairly well in predicting diurnal H2S lagoon flux trends.}, number={3}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Rumsey, Ian C. and Aneja, Viney P.}, year={2014}, month={Feb}, pages={1609–1617} }
 @article{rasheed_aneja_aiyyer_rafique_2014, title={Measurements and analysis of air quality in Islamabad, Pakistan}, volume={2}, ISSN={2328-4277}, url={http://dx.doi.org/10.1002/2013EF000174}, DOI={10.1002/2013EF000174}, abstractNote={Ambient air quality of Islamabad, Pakistan, reveals that annual average mass concentration of particulate matter (PM2.5) (∼45 to ∼95 µg m−3) and nitric oxide (NO) (∼41 to ∼120 µg m−3) exceeds the Pakistan's National Environmental Quality Standards (NEQS). The annual ozone (O3) concentration is within the permissible limits; however, some of the hourly concentration exceeds the NEQS mostly during the summer months. Correlation studies suggest that carbon monoxide (CO) has a significant (p‐value ≤ 0.01) positive correlation with NO and NOy′; whereas, with O3, a significant (p‐value ≤ 0.01) negative correlation is observed. The regression analysis estimates the background CO concentration to be ∼300 to ∼600 ppbv in Islamabad. The higher ratio of CO/NO (∼10) suggests that mobile sources are the major contributor to NO concentration. On the other hand, the ratio analysis of sulfur dioxide (SO2)/NO for Islamabad (∼0.011) indicates that the point sources are contributing to SO2 in the city. NO and SO2 correlation indicates contribution of direct sulfur emission sources. Ratios of [CO] to [NO] and [SO2] to [NO], based on ambient air quality measurements, provide a test for emission inventories. The ratios of these pollutants in the available Islamabad emission inventories are consistent with ambient values for these pollutants. The correlation of PM2.5 and NO suggests that a fraction of secondary PM2.5 is produced by chemical conversion of NO into nitrates. The regional background O3 concentration for Islamabad has been determined to be ∼31 ppbv. This study suggests that there is an increase in O3 concentration with increases in photochemical conversion of NO to reservoir NOy′ species.}, number={6}, journal={Earth's Future}, publisher={American Geophysical Union (AGU)}, author={Rasheed, Anjum and Aneja, Viney P. and Aiyyer, Anantha and Rafique, Uzaira}, year={2014}, month={Jun}, pages={303–314} }
 @inbook{aas_carou_alebic-juretic_aneja_balasubramanian_berge_cape_delon_denmead_dennis_et al._2014, title={Progress in nitrogen deposition monitoring and modelling}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84922990752&partnerID=MN8TOARS}, DOI={10.1007/978-94-007-7939-6_48}, booktitle={Nitrogen Deposition, Critical Loads and Biodiversity: Proceedings of the International Nitrogen Initiative Workshop, Linking Experts of the Convention on Long-Range Transboundary Air Pollution and the Convention on Biological Diversity}, author={Aas, W. and Carou, S. and Alebic-Juretic, A. and Aneja, V.P. and Balasubramanian, R. and Berge, H. and Cape, J.N. and Delon, C. and Denmead, O.T. and Dennis, R.L. and et al.}, year={2014}, pages={455–463} }
 @misc{behera_sharma_aneja_balasubramanian_2013, title={Ammonia in the atmosphere: a review on emission sources, atmospheric chemistry and deposition on terrestrial bodies}, volume={20}, ISSN={["1614-7499"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885897259&partnerID=MN8TOARS}, DOI={10.1007/s11356-013-2051-9}, number={11}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Behera, Sailesh N. and Sharma, Mukesh and Aneja, Viney P. and Balasubramanian, Rajasekhar}, year={2013}, month={Nov}, pages={8092–8131} }
 @inbook{rudek_aneja_2013, title={Climate Vulnerabilities of the Swine Industry}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902218558&partnerID=MN8TOARS}, DOI={10.1016/B978-0-12-384703-4.00217-3}, abstractNote={When considering how swine production will be affected by climate, perhaps the best place to start is to consider the present day vulnerabilities of the industry. The swine industry, like most of the meat production industry, is based on intensive production with trends suggesting future increases in intensification. This industry model depends on cheap grain, cheap energy, and manageable disease control. Some expect that future temperature, and precipitation frequency and intensity may have direct impacts on nonintensive swine production but are not likely to directly affect intensive production because the barn environment is controlled. However, there could be an increase in the frequency, intensity, and severity of both severe storms (e.g., hurricanes, tornadoes, etc.), which might increase the upset of large open-air lagoon treatment systems and flooding of barns. This could lead to increased pressure on intensive operations to modify current manure treatment systems. Climate effects could, thus, have negative impacts on feed grain production, which will affect its availability and price. Climate influences would also have indirect impacts on energy costs as demands for renewable energy increase, which could also put upward pressure on feed grain prices as bioenergy production competes for feed grains. The climate impacts on growth, reproductive success, and distribution of diseases may impact the ability to manage disease. This concern may be heightened in intensive production relative to nonintensive systems owing to the density of animals. Future greenhouse gas mitigation efforts may produce costs or revenue opportunities for the swine industry. Last, the role of reactive nitrogen (Nr) in climate and other intertwined issues could be very important. Swine producers will need to adapt to all these changes to maintain production levels.}, booktitle={Climate Vulnerability: Understanding and Addressing Threats to Essential Resources}, author={Rudek, J. and Aneja, V.P.}, year={2013}, pages={77–87} }
 @article{pillai_walker_khlystov_aneja_2013, title={Formation and Growth of Atmospheric Particles at a Forest Site in the Southeast US}, volume={1527}, ISSN={["0094-243X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84877358779&partnerID=MN8TOARS}, DOI={10.1063/1.4803288}, abstractNote={Atmospheric particle size distribution measurements (10 ≤ aerodynamic diameter, Dp ≤ 250 nm), which took place above a loblolly pine plantation in the Southeast U.S. from November 2005 to September 2007, were made using Scanning Mobility Particle Sizer (SMPS). The size distributions were investigated to identify new particle formation and to classify the new particle formation episodes into different event classes based on the behavior of particle size distribution and particle growth pattern. About 69% of the observation days had nucleation. The event frequency was highest in spring and lowest in winter. The particle growth rate was highest in May (5.0 ± 3.6 nm hr−1) and lowest in February (1.2 ± 2.2 nm hr−1) with an annual average particle growth rate of 2.5 ± 0.3 nm hr−1. Nucleation frequency and event types are examined along with associated meteorological and chemical conditions.}, journal={NUCLEATION AND ATMOSPHERIC AEROSOLS}, author={Pillai, Priya and Walker, John and Khlystov, Andrey and Aneja, Viney}, year={2013}, pages={401–404} }
 @article{pillai_khlystov_walker_aneja_2013, title={Observation and Analysis of Particle Nucleation at a Forest Site in Southeastern US}, volume={4}, ISSN={["2073-4433"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885125385&partnerID=MN8TOARS}, DOI={10.3390/atmos4020072}, abstractNote={This study examines the characteristics of new particle formation at a forest site in southeastern US. Particle size distributions above a Loblolly pine plantation were measured between November 2005 and September 2007 and analyzed by event type and frequency, as well as in relation to meteorological and atmospheric chemical conditions. Nucleation events occurred on 69% of classifiable observation days. Nucleation frequency was highest in spring. The highest daily nucleation (class A and B events) frequency (81%) was observed in April. The average total particle number concentration on nucleation days was 8,684 cm−3 (10 < Dp < 250 nm) and 3,991 cm−3 (10 < Dp < 25 nm) with a mode diameter of 28 nm with corresponding values on non-nucleation days of 2,143 cm−3, 655 cm−3, and 44.5 nm, respectively. The annual average growth rate during nucleation events was 2.7 ± 0.3 nm·h−1. Higher growth rates were observed during summer months with highest rates observed in May (5.0 ± 3.6 nm·h−1). Winter months were associated with lower growth rates, the lowest occurring in February (1.2 ± 2.2 nm·h−1). Consistent with other studies, nucleation events were more likely to occur on days with higher radiative flux and lower relative humidity compared to non-nucleation days. The daily minimum in the condensation sink, which typically occurred 2 to 3 h after sunrise, was a good indicator of the timing of nucleation onset. The intensity of the event, indicated by the total particle number concentration, was well correlated with photo-synthetically active radiation, used here as a surrogate for total global radiation, and relative humidity. Even though the role of biogenic VOC in the initial nuclei formation is not understood from this study, the relationships with chemical precursors and secondary aerosol products associated with nucleation, coupled with diurnal boundary layer dynamics and seasonal meteorological patterns, suggest that H2SO4 and biogenic VOC play a role in nucleated particle growth at this site.}, number={2}, journal={ATMOSPHERE}, author={Pillai, Priya and Khlystov, Andrey and Walker, John and Aneja, Viney}, year={2013}, month={Jun}, pages={72–93} }
 @article{aneja_isherwood_morgan_2012, title={Characterization of particulate matter (PM10) related to surface coal mining operations in Appalachia}, volume={54}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84859629113&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2012.02.063}, abstractNote={This study investigates the environmental exposure of residents of a community in southwest Virginia to respirable concentrations of dust (PM-10 i.e. PM10) generated by trucks hauling coal from surface coal mining operations. The study site is representative of communities in southwest Virginia and other parts of Appalachia that are located in narrow hollows where homes are placed directly along roads that experience heavy coal truck traffic. Preliminary air sampling (Particulate Matter i.e. PM10) was conducted for a period of approximately two weeks during early August 2008 in the unincorporated community of Roda, Virginia, at two locations (about a mile apart along Roda Road (Route 685) in Wise County, Virginia). For the purposes of this study (a combination of logistics, resource, and characterization of PM) we sited the PM samplers near the road to ascertain the micro exposure from the road. The results revealed high levels of PM10 (the mean adjusted 24-h concentration at the Campbell Site = 250.2 μg m−3 (±135.0 μg m−3); and at the Willis Site = 144.8 ± 60.0 μg m−3). The U.S. 24-h national ambient air quality standard for PM10 is 150 μg m−3. Elemental analysis for samples (blank-corrected) collected on Quartz filter paper (on one randomly selected day) at both the sites revealed the presence of antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium. Electron micrographs reveal the morphology and habit (shapes and aggregates) of the particulate matter collected.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Isherwood, Aaron and Morgan, Peter}, year={2012}, month={Jul}, pages={496–501} }
 @article{james_blunden_rumsey_aneja_2012, title={Characterizing ammonia emissions from a commercial mechanically ventilated swine finishing facility and an anaerobic waste lagoon in North Carolina}, volume={3}, ISSN={["1309-1042"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84881622224&partnerID=MN8TOARS}, DOI={10.5094/apr.2012.031}, abstractNote={Abstract Emissions of atmospheric ammonia–nitrogen [NH 3 –N, where NH 3 –N = (14/17) NH 3 ] were measured from a commercial anaerobic swine waste treatment lagoon and from an on–site finishing swine confinement house at the same location. Continuous measurements were made at each potential NH 3 –N source for ~1 week during four different seasons. Results presented here represent measurements made for the second year of a multi–year experiment. Barn emissions were estimated to be 2 604 ± 660 g NH 3 –N day −1 , 1 761 ± 1 087 g NH 3 –N day −1 , 1 657 ± 1 506 g NH 3 –N day −1 , and 2 659 ± 1 194 g NH 3 –N g day −1 in summer, fall, winter, and spring respectively. NH 3 –N barn emission factors were calculated to be 1.32 ± 0.32 kg NH 3 –N animal −1 yr −1 , 0.78 ± 0.49 kg NH 3 –N animal −1 yr −1 , 1.55 ± 1.40 kg NH 3 –N animal −1 yr −1 , and 1.35 ± 0.61 kg NH 3 –N animal −1 yr −1 in summer, fall, winter, and spring respectively. Average NH 3 –N flux from lagoon was greatest in the summer, >3 943 μg m −2 min −1 , and lowest in the winter, 981 ± 210 μg m −2 min −1 . Fall and spring average NH 3 –N flux values were >1 383 μg m −2 min −1 and 1 641 ± 362 μg m −2 min −1 , respectively.}, number={3}, journal={ATMOSPHERIC POLLUTION RESEARCH}, author={James, Kristen M. and Blunden, Jessica and Rumsey, Ian C. and Aneja, Viney P.}, year={2012}, month={Jul}, pages={279–288} }
 @article{rumsey_aneja_lonneman_2012, title={Characterizing non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation}, volume={47}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84155171266&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2011.10.055}, abstractNote={Emissions of non-methane volatile organic compounds (NMVOCs) were determined from a swine concentrated animal feeding operation (CAFO) in North Carolina. NMVOCs were measured in air samples collected in SUMMA and fused-silica lined (FSL) canisters and were analyzed using a gas chromatography flame ionization detection (GC–FID) system. Measurements were made from both an anaerobic lagoon and barn in each of the four seasonal sampling periods during the period June 2007 through April 2008. In each sampling period, nine to eleven canister samples were taken from both the anaerobic lagoon and barn over a minimum of four different days during a period of ∼1 week. Measurements of meteorological and physiochemical parameters were also made during the sampling period. In lagoon samples, six NMVOCs were identified that had significantly larger emissions in comparison to other NMVOCs. This included three alcohols (ethanol, 2-ethyl-1-hexanol, and methanol), two ketones (acetone and methyl ethyl ketone (MEK)) and an aldehyde (acetaldehyde). The overall average fluxes for these NMVOCs, ranged from 0.18 μg m−2 min−1 for 2-ethyl-1-hexanol to 2.11 μg m−2 min−1 for acetone, with seasonal fluxes highest in the summer for four (acetone, acetaldehyde, 2-ethyl-1-hexanol and MEK) of the six compounds In barn samples, there were six NMVOCs that had significantly larger concentrations and emissions in comparison to other NMVOCs. These consisted of two alcohols (methanol and ethanol), an aldehyde (acetaldehyde), two ketones (acetone and 2,3-butanedione), and a phenol (4-methylphenol). Overall average barn concentration ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. Overall average normalized barn emission rates ranged from 0.10 g day−1 AU−1 (1 AU (animal unit) = 500 kg of live animal weight) for acetaldehyde to 0.45 g day−1 AU−1 for ethanol. The NMVOCs, 4-methylphenol and 2,3-butanedione, which have low odor thresholds (odor thresholds = 1.86 ppb and 0.068–0.264 ppb for 4-methylphenol, and = 4.37 ppb and 1.42–7.39 ppb for 2-3-butanedione) and an offensive odor were identified in canister samples. Both 4-methylphenol and 2,3-butanedione barn concentrations exceeded their odor thresholds frequently. HAPs were identified in lagoon samples (methanol, acetaldehyde and MEK) and barn samples (methanol, acetaldehyde and 4-methylphenol) that were also classified as NMVOCs with significantly larger lagoon and barn emissions in comparison with other NMVOCs. The overall average lagoon fluxes and overall average normalized barn emissions for NMVOCs reported in this paper were used to estimate their North Carolina swine CAFO emissions. Of the NMVOCs, ethanol was estimated to have the largest North Carolina swine CAFO emission at 206,367 kg yr−1. The barns were found to have higher emissions than the lagoons for all NMVOCs, contributing between 68.6 to ∼100% of individual compounds estimated North Carolina swine CAFO emissions.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Rumsey, Ian C. and Aneja, Viney P. and Lonneman, William A.}, year={2012}, month={Feb}, pages={348–357} }
 @article{aneja_schlesinger_erisman_behera_sharma_battye_2012, title={Reactive nitrogen emissions from crop and livestock farming in India}, volume={47}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84155162902&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2011.11.026}, abstractNote={The rapid increase in anthropogenic nitrogen emissions to the atmosphere is matter of concern for the environment, as these may lead to photochemical air pollution, reduced visibility, eutrophication of surface waters, changes in biodiversity, acid rain, stratospheric ozone depletion, and global warming. In this study, ambient emissions of reactive nitrogen (ammonia and nitrous oxide) from animal and crop farming are analyzed for the base year 2003. This objective was achieved by the systematic development of a spatially resolved emissions inventory on a Geographic Information System (GIS) platform. Emissions of ammonia (NH3) and nitrous oxide (N2O) were estimated: (i) from livestock; 1705 Gg/yr and 214 Gg yr−1 and (ii) fertilizer applications; 2697 Gg yr−1 and 326 Gg yr−1. These estimated emissions were compared and contrasted with global, U.S., and European emissions of reactive nitrogen; emissions from India were second only to China. From the spatially resolved emission inventory, it was observed that the state of Uttar Pradesh has the highest NH3 emission (522 Gg yr−1) followed by the state of Maharashtra (425 Gg yr−1) both from animal and crop farming. Similarly the State of Uttar Pradesh has the highest N2O emission (70 Gg yr−1) followed by the state of Maharashtra (47 Gg yr−1).}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Schlesinger, William H. and Erisman, Jan Willem and Behera, Sailesh N. and Sharma, Mukesh and Battye, William}, year={2012}, month={Feb}, pages={92–103} }
 @article{aneja_aiyyer_hanna_shankar_adelman_arunachalam_trivikrama rao_mathur_david_ramaswamy_et al._2012, title={U.S-India collaboration on air quality and climate research and education}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84862995038&partnerID=MN8TOARS}, number={MARCH}, journal={EM: Air and Waste Management Association's Magazine for Environmental Managers}, author={Aneja, V.P. and Aiyyer, A. and Hanna, A. and Shankar, U. and Adelman, Z. and Arunachalam, S. and Trivikrama Rao, S. and Mathur, R. and David, J. and Ramaswamy, V. and et al.}, year={2012}, pages={30–36} }
 @inbook{erisman_bleeker_neftel_aneja_hutchings_kinsella_tang_webb_sponar_raes_et al._2009, title={Detecting change in atmospheric ammonia following emission changes}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84857729937&partnerID=MN8TOARS}, DOI={10.1007/978-1-4020-9121-6_23}, abstractNote={The Working Group discussed the progress on the state of knowledge on deriving trends from measurements and their use to verify abatement measures or other causes for decrease in emissions of ammonia to the atmosphere. The conclusions from the 2000 Berne meeting (Menzi and Achermann 2001), the background review (Bleeker et al. 2008) and presentations during the session (Horvath et al. 2008; Tang et al. 2008; Webb et al. 2008), as well as the discussions served as input for the conclusions of this report. We have seen some clear advancement in closing the gap between the observed and expected values for reduced nitrogen, where we do get a better understanding of the reasons behind it. The long-term measurements that are available follow the emission trend. Current measurements make it possible to evaluate policy progress on ammonia emission abatement. Especially in those countries where there were big (>25%) changes in emissions, such as in the Netherlands and Denmark the trend is followed quite closely, especially when meteorology is well taken into account. In order countries, such as the UK, the trend was much smaller, but there was no gap between measurements and model estimates. In the Netherlands there still is an ammonia gap: a significant (30%) difference between emissions based ammonia concentrations and measurements. The trend is the same. The difference might be due to either an underestimation of the emission or an overestimation of the dry deposition. It is recommended to further explore this gap, especially by investigating the high temporal resolution measurements, improving the emission/deposition modeling, by having a model intercomparison with countries that use models that do not show a gap and finally by doing a thorough uncertainty analysis.}, booktitle={Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts}, author={Erisman, J.W. and Bleeker, A. and Neftel, A. and Aneja, V. and Hutchings, N. and Kinsella, L. and Tang, Y.S. and Webb, J. and Sponar, M. and Raes, C. and et al.}, year={2009}, pages={383–390} }
 @inproceedings{erisman_bleeker_neftel_aneja_hutchings_kinsella_tang_webb_sponar_raes_et al._2009, title={Detecting change in atmospheric ammonia following emission changes}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84900525664&partnerID=MN8TOARS}, booktitle={Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts - Results of an Expert Workshop under the Convention on Long-Range Transboundary Air Pollution}, author={Erisman, J.W. and Bleeker, A. and Neftel, A. and Aneja, V. and Hutchings, N. and Kinsella, L. and Tang, Y.S. and Webb, J. and Sponar, M. and Raes, C. and et al.}, year={2009}, pages={383–390} }
 @article{aneja_schlesinger_erisman_2009, title={Effects of Agriculture upon the Air Quality and Climate: Research, Policy, and Regulations}, volume={43}, ISSN={["1520-5851"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-67449119222&partnerID=MN8TOARS}, DOI={10.1021/es8024403}, abstractNote={Scientific assessments of agricultural air quality, including estimates of emissions and potential sequestration of greenhouse gases, are an important emerging area of environmental science that offers significant challenges to policy and regulatory authorities. Improvements are needed in measurements, modeling, emission controls, and farm operation management. Controlling emissions of gases and particulate matter from agriculture is notoriously difficult as this sector affects the most basic need of humans, i.e., food. Current policies combine an inadequate science covering a very disparate range of activities in a complex industry with social and political overlays. Moreover, agricultural emissions derive from both area and point sources. In the United States, agricultural emissions play an important role in several atmospherically mediated processes of environmental and public health concerns. These atmospheric processes affect local and regional environmental quality, including odor, particulate matter (PM) exposure, eutrophication, acidification, exposure to toxics, climate, and pathogens. Agricultural emissions also contribute to the global problems caused by greenhouse gas emissions. Agricultural emissions are variable in space and time and in how they interact within the various processes and media affected. Most important in the U.S. are ammonia (where agriculture accounts for approximately 90% of total emissions), reduced sulfur (unquantified), PM25 (approximately 16%), PM110 (approximately 18%), methane (approximately 29%), nitrous oxide (approximately 72%), and odor and emissions of pathogens (both unquantified). Agriculture also consumes fossil fuels for fertilizer production and farm operations, thus emitting carbon dioxide (CO2), oxides of nitrogen (NO(x)), sulfur oxides (SO(x)), and particulates. Current research priorities include the quantification of point and nonpoint sources, the biosphere-atmosphere exchange of ammonia, reduced sulfur compounds, volatile organic compounds, greenhouse gases, odor and pathogens, the quantification of landscape processes, and the primary and secondary emissions of PM. Given the serious concerns raised regarding the amount and the impacts of agricultural air emissions, policies must be pursued and regulations must be enacted in orderto make real progress in reducing these emissions and their associated environmental impacts.}, number={12}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Aneja, Viney P. and Schlesinger, William H. and Erisman, Jan Willem}, year={2009}, month={Jun}, pages={4234–4240} }
 @inbook{bleeker_sutton_acherman_alebic-juretic_aneja_ellermann_erisman_fowler_fagerli_gauger_et al._2009, title={Linking ammonia emission trends to measured concentrations and deposition of reduced nitrogen at different scales}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885706269&partnerID=MN8TOARS}, DOI={10.1007/978-1-4020-9121-6_11}, booktitle={Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts}, author={Bleeker, A. and Sutton, M.A. and Acherman, B. and Alebic-Juretic, A. and Aneja, V.P. and Ellermann, T. and Erisman, J.W. and Fowler, D. and Fagerli, H. and Gauger, T. and et al.}, year={2009}, pages={123–180} }
 @inproceedings{bleeker_sutton_acherman_alebic-juretic_aneja_ellermann_erisman_fowler_fagerli_gauger_et al._2009, title={Linking ammonia emission trends to measured concentrations and deposition of reduced nitrogen at different scales}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84900541568&partnerID=MN8TOARS}, booktitle={Atmospheric Ammonia: Detecting Emission Changes and Environmental Impacts - Results of an Expert Workshop under the Convention on Long-Range Transboundary Air Pollution}, author={Bleeker, A. and Sutton, M.A. and Acherman, B. and Alebic-Juretic, A. and Aneja, V.P. and Ellermann, T. and Erisman, J.W. and Fowler, D. and Fagerli, H. and Gauger, T. and et al.}, year={2009}, pages={123–180} }
 @article{aneja_schlesinger_2008, title={A special issue of JA&WMA on agricultural air quality: State of the science - Introduction}, volume={58}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849121300&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1113}, abstractNote={The world’s population has grown, from approximately 1.5 billion at the beginning of the 20th century to more than 6 billion today. This population increase has been accompanied by the rapid growth of intensive agriculture with its associated, significant impacts on the environment. Over the next 50 yr, the Earth’s human population is predicted to increase from the current level to more than 9 billion, creating a parallel or disproportionate increase in demand for agricultural commodities— both crop and animal. Without scientific research to inform policy decisions, there will likely be greater environmental impacts associated with this future growth.1–3 Though in transition, U.S. agriculture is still diverse, ranging from large, highly intensive and specialized commercial holdings to subsistence (i.e., family owned) farming, using mainly traditional practices. Consequently, impacts on the environment vary in scale and intensity and may be positive or negative. However, an increasing body of evidence shows that the increased size and geographical concentration of animal-feeding operations and agri}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Schlesinger, William H.}, year={2008}, month={Sep}, pages={1113–1115} }
 @article{aneja_blunden_james_schlesinger_knighton_gilliam_jennings_niyogi_cole_2008, title={Ammonia assessment from agriculture: US status and needs}, volume={37}, ISSN={["1537-2537"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-40849136515&partnerID=MN8TOARS}, DOI={10.2134/jeq2007.0002in}, abstractNote={Recent studies suggest that human activities accelerate the production of reactive nitrogen on a global scale. Increased nitrogen emissions may lead to environmental impacts including photochemical air pollution, reduced visibility, changes in biodiversity, and stratospheric ozone depletion. In the last 50 yr, emissions of ammonia (NH3), which is the most abundant form of reduced reactive nitrogen in the atmosphere, have significantly increased as a result of intensive agricultural management and greater livestock production in many developed countries. These agricultural production practices are increasingly subject to governmental regulations intended to protect air resources. It is therefore important that an accurate and robust agricultural emission factors database exist to provide valid scientific support of these regulations. This paper highlights some of the recent work that was presented at the 2006 Workshop on Agricultural Air Quality in Washington, D.C. regarding NH3 emissions estimates and emission factors from agricultural sources in the U.S. and Europe. In addition, several best management practices are explored as the scientific community attempts to maximize the beneficial use of reactive nitrogen while simultaneously minimizing negative environmental impacts.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Aneja, Viney P. and Blunden, Jessica and James, Kristen and Schlesinger, William H. and Knighton, Raymond and Gilliam, Wendell and Jennings, Greg and Niyogi, Dev and Cole, Shawn}, year={2008}, pages={515–520} }
 @inproceedings{gore_aneja_konarik_blunden_2008, title={An apparent paradox: Agricultural ammonia emissions and the National Atmospheric Deposition Network}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70349900136&partnerID=MN8TOARS}, booktitle={Air and Waste Management Association: Symposium on Air Quality Measurement Methods and Technology 2008}, author={Gore, M.L. and Aneja, V.P. and Konarik, S. and Blunden, J.}, year={2008}, pages={380–383} }
 @article{occhipinti_aneja_showers_niyogi_2008, title={Back-trajectory analysis and source-receptor relationships: Particulate matter and nitrogen isotopic composition in rainwater}, volume={58}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849144360&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1215}, abstractNote={Abstract The southeastern portion of North Carolina features a dense crop and animal agricultural region; previous research suggests that this agricultural presence emits a significant portion of the state’s nitrogen (i.e., oxides of nitrogen and ammonia) emissions. These findings indicate that transporting air over this region can affect nitrogen concentrations in precipitation at sites as far as 50 mi away. The study combined nitrate nitrogen isotope data with back-trajectory analysis to examine the relationship between regional nitrogen emission estimates independent of pollutant concentration information. In 2004, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to determine potential sources of nitrogen in rainwater collected at an urban receptor site in Raleigh, NC. The δ15N isotope ratio signatures of each sample were used to further differentiate between sources of the rainwater nitrate. This study examined the importance of pollution sources, including animal agricultural activity, and meteorology on rainfall chemistry as well as the implications in fine particulate matter (PM2.5) formation. Samples that transited the dense crop and animal (swine) agricultural region of east-southeastern North Carolina (i.e., the source region) had lower δ15N isotope ratios in the nitrate ion (average = −2.1 ± 1.7‰) than those from a counterpart nonagricultural region (average = 0.1 ± 3‰.) An increase in PM2.5 concentrations in the urban receptor site (yearly average = 15.1 ± 5.8 μg/m3) was also found to correspond to air transport over the dense agricultural region relative to air that was not subjected to such transport (yearly average = 11.7 ± 5.8 μg/m3).}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Occhipinti, Chris and Aneja, Viney P. and Showers, William and Niyogi, Dev}, year={2008}, month={Sep}, pages={1215–1222} }
 @article{blunden_aneja_2008, title={Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449084288&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.02.026}, abstractNote={Emissions of atmospheric ammonia–nitrogen (NH3-N, where NH3-N=(14/17)NH3) and hydrogen sulfide (H2S) from a commercial anaerobic swine waste treatment lagoon (17,150 m2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for ∼1 week during four seasons, October–November 2004 (fall), February 2005 (winter), April 2005 (spring), and June 2005 (summer) in an effort to examine diurnal and seasonal variability, and the respective relationships of NH3-N and H2S emissions to lagoon physicochemical properties. Continuously measured lagoon physicochemical parameters include lagoon surface temperature and lagoon pH. Aqueous lagoon samples were collected daily and analyzed for total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), and total sulfide concentration. TKN, TAN, and sulfide concentrations ranged from 400–650, 360–590, and 0.1–13.0 mg L−1, respectively. For NH3-N, the largest fluxes were observed during the summer (>4200 μg N m−2 min−1). During the fall and spring, average NH3-N fluxes were 1634±505 and >2495 μg N m−2 min−1, respectively. The lowest fluxes were observed during the winter where average flux values were 1290±246 μg N m−2 min−1. Fluxes for H2S were negligible during the winter season. Average fluxes increased during the fall (0.3±0.1 μg m−2 min−1) and spring (0.5±1.0 μg m−2 min−1), and highest flux values were observed during the summer (5.3±3.2 μg m−2 min−1). The seasonal NH3-N and H2S emission factors ranged from ∼10 to ∼40 kg N AU−1 yr−1 (1 AU=500 kg live animal weight) and ∼0 to ∼0.05 kg H2S AU−1 yr−1, respectively. Generally, the lagoon emissions for H2S were ∼3–4 orders of magnitude less than NH3-N. The gas fluxes were related to various physicochemical parameters including the pH and near-surface temperature of the lagoon, and the aqueous concentration of the respective gas.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P.}, year={2008}, month={Apr}, pages={3277–3290} }
 @article{aneja_arya_rumsey_kim_bajwa_arkinson_semunegus_dickey_stefanski_todd_et al._2008, title={Characterizing ammonia emissions from swine farms in eastern North Carolina: Part 2 - Potential environmentally superior technologies for waste treatment}, volume={58}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849100726&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1145}, abstractNote={Abstract The need for developing environmentally superior and sustainable solutions for managing the animal waste at commercial swine farms in eastern North Carolina has been recognized in recent years. Program OPEN (Odor, Pathogens, and Emissions of Nitrogen), funded by the North Carolina State University Animal and Poultry Waste Management Center (APWMC), was initiated and charged with the evaluation of potential environmentally superior technologies (ESTs) that have been developed and implemented at selected swine farms or facilities. The OPEN program has demonstrated the effectiveness of a new paradigm for policy-relevant environmental research related to North Carolina’s animal waste management programs. This new paradigm is based on a commitment to improve scientific understanding associated with a wide array of environmental issues (i.e., issues related to the movement of N from animal waste into air, water, and soil media; the transmission of odor and odorants; disease-transmitting vectors; and airborne pathogens). The primary focus of this paper is on emissions of ammonia (NH3) from some potential ESTs that were being evaluated at full-scale swine facilities. During 2-week-long periods in two different seasons (warm and cold), NH3 fluxes from water-holding structures and NH3 emissions from animal houses or barns were measured at six potential EST sites: (1) Barham farm—in-ground ambient temperature anaerobic digester/energy recovery/greenhouse vegetable production system; (2) BOC #93 farm—upflow biofiltration system—EKOKAN ; (3) Carrolls farm—aerobic blanket system—ISSUES-ABS; (4) Corbett #1 farm—solids separation/gasification for energy and ash recovery centralized system—BEST; (5) Corbett #2 farm—solid separation/reciprocating water technology—ReCip; and (6) Vestal farm—Recycling of Nutrient, Energy and Water System—ISSUES—RENEW. The ESTs were compared with similar measurements made at two conventional lagoon and spray technology (LST) farms (Moore farm and Stokes farm). A flow-through dynamic chamber system and two sets of open-path Fourier transform infrared (OP-FTIR) spectrometers measured NH3 fluxes continuously from water-holding structures and emissions from housing units at the EST and conventional LST sites. A statisticalobservational model for lagoon NH3 flux was developed using a multiple linear regression analysis of 15-min averaged NH3 flux data against the relevant environmental parameters measured at the two conventional farms during two different seasons of the year. This was used to compare the water-holding structures at ESTs with those from lagoons at conventional sites under similar environmental conditions. Percentage reductions in NH3 emissions from different components of each potential EST, as well as the whole farm on which the EST was located were evaluated from the estimated emissions from water-holding structures, barns, etc., all normalized by the appropriate nitrogen excretion rate at the potential EST farm, as well as from the appropriate conventional farm. This study showed that ammonia emissions were reduced by all but one potential EST for both experimental periods. However, on the basis of our evaluation results and analysis and available information in the scientific literature, the evaluated alternative technologies may require additional technical modifications to be qualified as unconditional ESTs relative to NH3 emissions reductions.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Arya, S. Pal and Rumsey, Ian C. and Kim, D. -S. and Bajwa, K. and Arkinson, H. L. and Semunegus, H. and Dickey, D. A. and Stefanski, L. A. and Todd, L. and et al.}, year={2008}, month={Sep}, pages={1145–1157} }
 @article{aneja_arya_rumsey_kim_bajwa_williams_2008, title={Characterizing ammonia emissions from swine farms in eastern North Carolina: Reduction of emissions from water-holding structures at two candidate superior technologies for waste treatment}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449117100&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.08.037}, abstractNote={Abstract Program OPEN (Odor, Pathogens, and Emissions of Nitrogen) was an integrated study of the emissions of ammonia (NH 3 ), odor and odorants, and pathogens from potential environmentally superior technologies (ESTs) for swine facilities in eastern North Carolina. This paper, as part of program OPEN, focuses on quantifying emissions of NH 3 from water-holding structures at two of the best ESTs and compares them with the projected emissions from two conventional lagoon and spray technologies (LSTs). The evaluated ESTs are: (1) Super Soils at Goshen Ridge; and (2) Environmental Technologies at Red Hill. The water-holding structures for these two ESTs contained no conventional anaerobic lagoon. A dynamic flow-through chamber was used to measure NH 3 fluxes from the water-holding structures at both the ESTs and at the conventional LST farms. In order to compare the emissions from the water-holding structures at the ESTs with those from the lagoons at the conventional sites under similar conditions, a statistical-observational model for lagoon NH 3 emissions was used. A mass-balance approach was used to quantify the emissions. All emissions were normalized by nitrogen-excretion rates. The percentage reductions relative to the conventional lagoons were calculated for the two ESTs. Results showed substantial reductions in NH 3 emissions at both ESTs. Super Soils had reductions of 94.7% for the warm season and 99.0% for the cool season. Environmental Technologies had slightly larger reductions of 99.4% and 99.98% for the cool and warm season, respectively. As a result of such large reductions in ammonia emissions, both technologies meet the criteria to be classified as ESTs for ammonia emissions.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Arya, S. Pal and Rumsey, Ian C. and Kim, D-S. and Bajwa, K. S. and Williams, C. M.}, year={2008}, month={Apr}, pages={3291–3300} }
 @article{aneja_arya_kim_rumsey_arkinson_semunegus_bajwa_dickey_stefanski_todd_et al._2008, title={Characterizing ammonia emissions from swine farms in eastern north carolina: Part 1-conventional lagoon and spray technology for waste treatment}, volume={58}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849107841&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1130}, abstractNote={Abstract Ammonia (NH3) fluxes from waste treatment lagoons and barns at two conventional swine farms in eastern North Carolina were measured. The waste treatment lagoon data were analyzed to elucidate the temporal (seasonal and diurnal) variability and to derive regression relationships between NH3 flux and lagoon temperature, pH and ammonium content of the lagoon, and the most relevant meteorological parameters. NH3 fluxes were measured at various sampling locations on the lagoons by a flow-through dynamic chamber system interfaced to an environmentally controlled mobile laboratory. Two sets of open-path Fourier transform infrared (FTIR) spectrometers were also used to measure NH3 concentrations for estimating NH3 emissions from the animal housing units (barns) at the lagoon and spray technology (LST) sites.Two different types of ventilation systems were used at the two farms. Moore farm used fan ventilation, and Stokes farm used natural ventilation. The early fall and winter season intensive measurement campaigns were conducted during September 9 to October 11, 2002 (lagoon temperature ranged from 21.2 to 33.6 °C) and January 6 to February 2, 2003 (lagoon temperature ranged from 1.7 to 12 °C), respectively. Significant differences in seasonal NH3 fluxes from the waste treatment lagoons were found at both farms. Typical diurnal variation of NH3 flux with its maximum value in the afternoon was observed during both experimental periods. Exponentially increasing flux with increasing surface lagoon temperature was observed, and a linear regression relationship between logarithm of NH3 flux and lagoon surface temperature (T l) was obtained. Correlations between lagoon NH3 flux and chemical parameters, such as pH, total Kjeldahl nitrogen (TKN), and total ammoniacal nitrogen (TAN) were found to be statistically insignificant or weak. In addition to lagoon surface temperature, the difference (D) between air temperature and the lagoon surface temperature was also found to influence the NH3 flux, especially when D > 0 (i.e., air hotter than lagoon). This hot-air effect is included in the statistical-observational model obtained in this study, which was used further in the companion study (Part II), to compare the emissions from potential environmental superior technologies to evaluate the effectiveness of each technology.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Arya, S. Pal and Kim, D. -S. and Rumsey, Ian C. and Arkinson, H. L. and Semunegus, H. and Bajwa, K. S. and Dickey, D. A. and Stefanski, L. A. and Todd, L. and et al.}, year={2008}, month={Sep}, pages={1130–1144} }
 @inproceedings{rumsey_aneja_lonneman_2008, title={Characterizing sulfur compound emissions from a hog farm in eastern North Carolina}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70349976913&partnerID=MN8TOARS}, booktitle={Air and Waste Management Association: Symposium on Air Quality Measurement Methods and Technology 2008}, author={Rumsey, I.C. and Aneja, V.P. and Lonneman, W.A.}, year={2008}, pages={484–490} }
 @article{aneja_schlesinger_erisman_2008, title={Farming pollution}, volume={1}, ISSN={["1752-0894"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849123202&partnerID=MN8TOARS}, DOI={10.1038/ngeo236}, number={7}, journal={NATURE GEOSCIENCE}, author={Aneja, Viney P. and Schlesinger, William H. and Erisman, Jan Willem}, year={2008}, month={Jul}, pages={409–411} }
 @article{blunden_aneja_westerman_2008, title={Measurement and analysis of ammonia and hydrogen sulfide emissions from a mechanically ventilated swine confinement building in North Carolina}, volume={42}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449109456&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.06.040}, abstractNote={Emissions of atmospheric ammonia–nitrogen (NH3–N, where NH3–N=(1417)NH3) and hydrogen sulfide (H2S) were measured from a finishing swine confinement house at a commercial pig farm in eastern North Carolina. Continuous simultaneous NH3–N and H2S emissions were made for ∼1-week period during four different seasons. The number of pigs contained in the house varied from ∼850 to 900 with average weights ranging from ∼38 to 88 kg. Average NH3–N concentrations were highest during the winter and spring sampling periods, 8.91±4.61 and 8.44±2.40 ppm, respectively, and lower during the summer and fall, 2.45±1.14 and 4.27±0.71 ppm, respectively. Measured average H2S concentrations were 673±282, 429±223, 47±18, and 304±88 ppb during winter, spring, summer, and fall, respectively. Generally, the H2S concentrations were approximately an order of magnitude less than NH3–N during winter, spring, and fall, and two orders of magnitude smaller during the summer season. The average ambient temperature ranged from 5.5 to 22.3 °C while the average barn temperature measured at the outlet fans ranged from 19.0 to 26.0 °C in the winter and summer, respectively. The average fan ventilation rates varied from 253 m3 min−1 during the fall sampling period to 1024 m3 min−1 during summer. Calculated total emission rates for both NH3–N and H2S were highest during the spring, 4519±1639 g N day−1 and 481±142 g day−1, respectively. Emissions were lowest during the fall season for NH3–N (904±568 g N day−1) and the summer season for H2S (82±49 g day−1). Normalized NH3–N emission rates were highest in winter and spring (33.6±21.9 and 30.6±11.1 g N day−1 AU−1, where 1 AU (animal unit)=500 kg) and lowest during summer and fall (24.3±12.4 and 11.8±7.4 g N day−1 AU−1). Normalized H2S emissions were highest during the winter and spring seasons (4.2±2.1 and 3.3±1.0 g day−1 AU−1) and were lowest in summer and fall (1.2±0.7 and 1.7±0.5 g day−1 AU−1).}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P. and Westerman, Phillip W.}, year={2008}, month={Apr}, pages={3315–3331} }
 @article{goetz_aneja_zhang_2008, title={Measurement, analysis, and modeling of fine particulate matter in eastern North Carolina}, volume={58}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53149087232&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1208}, abstractNote={Abstract An analysis of fine particulate data in eastern North Carolina was conducted to investigate the impact of the hog industry and its emissions of ammonia into the atmosphere. The fine particulate data are simulated using ISORROPIA, an equilibrium thermodynamic model that simulates the gas and aerosol equilibrium of inorganic atmospheric species. The observational data analyses show that the major constituents of fine particulate matter (PM2.5) are organic carbon, elemental carbon, sulfate, nitrate, and ammonium. The observed PM2.5 concentration is positively correlated with temperature but anticor-related with wind speed. The correlation between PM2.5 and wind direction at some locations suggests an impact of ammonia emissions from hog facilities on PM2.5 formation. The modeled results are in good agreement with observations, with slightly better agreement at urban sites than at rural sites. The predicted total inorganic particulate matter (PM) concentrations are within 5% of the observed values under conditions with median initial total PM species concentrations, median relative humidity (RH), and median temperature. Ambient conditions with high PM precursor concentrations, low temperature, and high RH appear to favor the formation of secondary PM.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Goetz, Stephen and Aneja, Viney P. and Zhang, Yang}, year={2008}, month={Sep}, pages={1208–1214} }
 @article{zhang_wu_krishnan_wang_queen_aneja_arya_2008, title={Modeling agricultural air quality: Current status, major challenges, and outlook}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41549095063&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.01.063}, abstractNote={Agricultural air quality is an important emerging area of atmospheric sciences that represents significant challenges in many aspects of research including measurements, modeling, regulations, emission control, and operation managements. This work presents a review of current status, major challenges, and future research needs and opportunities of several important aspects of agricultural air quality modeling including chemical species, concentration and deposition measurements for model verification, emission inventories, major physical and chemical processes, model application and evaluation, and policy implications.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Zhang, Yang and Wu, Shiang-Yuh and Krishnan, Srinath and Wang, Kai and Queen, Ashley and Aneja, Viney P. and Arya, S. Pal}, year={2008}, month={Apr}, pages={3218–3237} }
 @article{wu_hu_zhang_aneja_2008, title={Modeling atmospheric transport and fate of ammonia in North Carolina - Part II: Effect of ammonia emissions on fine particulate matter formation}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449110003&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.04.022}, abstractNote={Accurate estimates of ammonia (NH3) emissions are needed for reliable predictions of fine particulate matter (PM2.5) by air quality models (AQMs), but the current estimates contain large uncertainties in the temporal and spatial distributions of NH3 emissions. In this study, the US EPA Community Multiscale Air Quality (CMAQ) modeling system is applied to study the contributions of the agriculture–livestock NH3 (AL-NH3) emissions to the concentration of PM2.5 and the uncertainties in the total amount and the temporal variations of NH3 emissions and their impact on the formation of PM2.5 for August and December 2002. The sensitivity simulation results show that AL-NH3 emissions contribute significantly to the concentration of PM2.5, NH4+, and NO3−; their contributions to the concentrations of SO42− are relatively small. The impact of NH3 emissions on PM2.5 formation shows strong spatial and seasonal variations associated with the meteorological conditions and the ambient chemical conditions. Increases in NH3 emissions in August 2002 resulted in >10% increases in the concentrations of NH4+ and NO3−; reductions in NH3 emissions in December 2002 resulted in >20% decreases in their concentrations. The large changes in species concentrations occur downwind of the high NH3 emissions where the ambient environment is NH3-poor or neutral. The adjustments in NH3 emissions improve appreciably the model predictions of NH4+ and NO3− both in August and December, but resulted in negligible improvements in PM2.5 in August and a small improvement in December, indicating that other factors (e.g., inaccuracies in meteorological predictions, emissions of other primary species, aerosol treatments) might be responsible for model biases in PM2.5.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Wu, Shiang-Yuh and Hu, Jian-Lin and Zhang, Yang and Aneja, Viney P.}, year={2008}, month={Apr}, pages={3437–3451} }
 @article{wu_krishnan_zhang_aneja_2008, title={Modeling atmospheric transport and fate of ammonia in North Carolina-Part I: Evaluation of meteorological and chemical predictions}, volume={42}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449096822&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.04.031}, abstractNote={The atmospheric transport and fate of ammonia (NH3) depend on both meteorological and chemical conditions once it is emitted into the atmosphere. The largest source contributing to NH3 emission is the agricultural production, in particular animal operation, in North Carolina (NC). In this study, three-dimensional numerical meteorological and air quality models are applied to study the transport and fate of NH3 in the atmosphere in an area in southeast US centered over NC. One summer and one winter month simulations with a 4-km horizontal grid were conducted to simulate the meteorological and chemical environments for the transport and transformation of the reduced nitrogen, NHx (=NH3+NH4+) and to examine its seasonal variations and interactions with other chemical species (e.g., ozone and fine particular matter, PM2.5). The model performance for simulated meteorology and air quality was evaluated against observations in terms of spatial distributions, temporal variations, and statistical trends. MM5/CMAQ gave an overall good performance for meteorological variables and O3 mixing ratios and a reasonably good performance for PM2.5. The simulations show that 10–40% of total NH3 was converted to NH4+ at/near source and 40–100% downwind in August, and the conversion rates were 20–50% at/near source and 50–98% downwind in December. While the 3-D atmospheric models demonstrate some skills in capturing synoptic meteorological patterns, diurnal variations of concentrations of oxidants and PM2.5, and regional transport and transformation of NHx, reproducing meteorological and chemical features at a local scale and the magnitudes of hourly concentrations of oxidants and PM2.5 remain challenging due to uncertainties in model inputs and treatments.}, number={14}, journal={Atmospheric Environment}, author={Wu, S.-Y. and Krishnan, S. and Zhang, Y. and Aneja, Viney}, year={2008}, pages={3419–3436} }
 @article{blunden_aneja_overton_2008, title={Modeling hydrogen sulfide emissions across the gas-liquid interface of an anaerobic swine waste treatment storage system}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-46749153762&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2008.03.016}, abstractNote={Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive “rotten egg” smell and is considered a toxic manure gas. In the southeastern United States, anaerobic waste treatment lagoons are widely used to store and treat hog excreta at commercial hog farms. Hydrogen sulfide is produced as manure decomposes anaerobically, resulting from the mineralization of organic sulfur compounds as well as the reduction of oxidized inorganic sulfur compounds by sulfur-reducing bacteria. The process of H2S emissions from anaerobic waste treatment lagoons are investigated utilizing a two-film model with three different modeling approaches: Coupled Mass Transfer with Chemical Reactions Model with the assumption (1) pH remains constant in the liquid film (MTCR Model I) and (2) pH may change throughout the liquid film due to diffusion processes that occur within the film (MTCR Model II); and (3) a Mass Transfer Model which neglects chemical reactions (MTNCR Model) in the gas and liquid films. Results of model predictions are consistent with previous works, which show that flux is largely dependent on the physicochemical lagoon properties including sulfide concentration, pH, and lagoon temperature. Air temperature and low wind velocities (e.g., <3.25 m s−1) have negligible impact on flux. Results also indicate that flux values decrease with increased film thickness. The flux was primarily influenced by variations in the liquid film thickness, signifying that the H2S flux is driven by liquid-phase parameters. Model results were compared with H2S flux measurements made at a swine waste treatment storage lagoon in North Carolina using a dynamic emission flux chamber system in order to evaluate model accuracy in calculating lagoon H2S emissions. The MTCR Model II predicted the highest increase in emission rates as aqueous sulfide concentration was increased. The MTNCR Model showed the highest dependence on pH. All three models showed good agreement in diurnal comparison with flux measurements; however, each model significantly over predicted the measured flux rates. The MTNCR Model estimates were closest to experimental values, predicting 3–35 times the actual measured values.}, number={22}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, Jessica and Aneja, Viney P. and Overton, John H.}, year={2008}, month={Jul}, pages={5602–5611} }
 @article{bajwa_arya_aneja_2008, title={Modeling studies of ammonia dispersion and dry deposition at some hog farms in North Carolina}, volume={58}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-53849137372&partnerID=MN8TOARS}, DOI={10.3155/1047-3289.58.9.1198}, abstractNote={Abstract A modeling study was conducted on dispersion and dry deposition of ammonia taking one hog farm as a unit. The ammonia emissions used in this study were measured under our OPEN (Odor, Pathogens, and Emissions of Nitrogen) project over a waste lagoon and from hog barns. Meteorological data were also collected at the farm site. The actual layout of barns and lagoons on the farms was used to simulate dry deposition downwind of the farm. Dry deposition velocity, dispersion, and dry deposition of ammonia were studied over different seasons and under different stability conditions using the short-range dispersion/air quality model, AERMOD. Dry deposition velocities were highest under near-neutral conditions and lowest under stable conditions. The highest deposition at short range occurred under nighttime stable conditions and the lowest occurred during daytime unstable conditions. Significant differences in deposition over crop and grass surfaces were observed under stable conditions.}, number={9}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Bajwa, Kanwardeep S. and Arya, S. Pal and Aneja, Viney P.}, year={2008}, month={Sep}, pages={1198–1207} }
 @article{stephen_aneja_2008, title={Trends in agricultural ammonia emissions and ammonium concentrations in precipitation over the Southeast and Midwest United States}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449098963&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.05.062}, abstractNote={Emissions from agricultural activities, both crop and animal, are known to contain gaseous ammonia (NH3) which through chemical reaction in rainwater changes into ammonium ion (NH4+). Using wet deposition data of ammonium from several National Atmospheric Deposition Program/National Trends Network (NADP/NTN) and ambient levels of ammonium from Clean Air Status Trends Network (CAST Net) sites as well as calculated NH3 emissions from North Carolina, and the Southeast and Midwest regions of the United States, trends in ammonium concentrations in precipitation were analyzed for the period of 1983–2004. The beginning of 1997 coincides with the implementation of a swine population moratorium in the state of North Carolina. Results from the analysis in North Carolina indicate a lessening in the rate of increases in NH4+ concentration in precipitation since the moratorium went into effect. Sampson County, NC, saw stable NH4+ concentrations from 1983 to 1989, an average rise of 9.5% from 1989 to 1996, and an average increase of only 4% from 1997 to 2004. In addition, HYSPLIT back-trajectory model was used to determine that when ambient air in downwind sites arrived from the high NH3 emissions source region, ammonium concentrations in precipitation were enhanced. For the Southeast United States domain, analysis shows that NH4+ concentrations generally increased with increasing NH3 emissions from within the same region. Similar analysis has been performed over the Midwest United States and compared to the results from the Southeast United States. Emissions from the Midwest are attributed to larger animals, including hogs and cattle, whereas the Southeast has a higher percentage of emissions coming from smaller livestock, such as chickens. In addition, the states of the Midwest United States have a much more uniform spatial distribution of emissions.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Stephen, Konarik and Aneja, Viney P.}, year={2008}, month={Apr}, pages={3238–3252} }
 @article{aneja_blunden_roelle_schlesinger_knighton_niyogi_gilliam_jennings_duke_2008, title={Workshop on Agricultural Air Quality: State of the science}, volume={42}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41449102642&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2007.07.043}, abstractNote={The first Workshop on Agricultural Air Quality: State of the Science was held at the Bolger Center in Potomac, Maryland from 4 to 8 June 2006. This international conference assembled approximately 350 people representing 25 nations from 5 continents, with disciplines ranging from atmospheric chemistry to soil science. The workshop was designed as an open forum in which participants could openly exchange the most current knowledge and learn about numerous international perspectives regarding agricultural air quality. Participants represented many stakeholder groups concerned with the growing need to assess agricultural impacts on the atmosphere and to develop beneficial policies to improve air quality. The workshop focused on identifying methods to improve emissions inventories and best management practices for agriculture. Workshop participants also made recommendations for technological and methodological improvements in current emissions measurement and modeling practices. The workshop commenced with a session on agricultural emissions and was followed by international perspectives from the United States, Europe, Australia, India, and South America. This paper summarizes the findings and issues of the workshop and articulates future research needs. These needs were identified in three general areas: (1) improvement of emissions measurement; (2) development of appropriate emission factors; and (3) implementation of best management practices (BMPs) to minimize negative environmental impacts. Improvements in the appropriate measurements will inform decisions regarding US farming practices. A need was demonstrated for a national/international network to monitor atmospheric emissions from agriculture and their subsequent depositions to surrounding areas. Information collected through such a program may be used to assess model performance and could be critical for evaluating any future regulatory policies or BMPs. The workshop concluded that efforts to maximize benefits and reduce detrimental effects of agricultural production need to transcend disciplinary, geographic, and political boundaries. Also, such efforts should involve natural and social scientists, economists, engineers, business leaders, and decision makers. The workshop came to the conclusion that through these collaborative efforts improvements in air quality from agricultural practices will begin to take effect.}, number={14}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, Viney P. and Blunden, Jessica and Roelle, Paul A. and Schlesinger, William H. and Knighton, Raymond and Niyogi, Dev and Gilliam, Wendell and Jennings, Greg and Duke, Clifford S.}, year={2008}, month={Apr}, pages={3195–3208} }
 @inproceedings{blunden_aneja_2007, title={Measurements and modeling of ammonia and hydrogen sulfide emissions from a commercial swine finishing operation in North Carolina}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84933528204&partnerID=MN8TOARS}, booktitle={100th Annual Conference and Exhibition of the Air and Waste Management Association 2007, ACE 2007}, author={Blunden, J. and Aneja, V.P.}, year={2007}, pages={330–342} }
 @inbook{aneja_tong_kang_ray_2007, place={Boston, MA}, title={Modeling and Analysis of Ozone and Nitrogen Oxides in the Southeast United States National Parks}, ISBN={9780387282558}, url={http://dx.doi.org/10.1007/978-0-387-68854-1_2}, DOI={10.1007/978-0-387-68854-1_2}, booktitle={Air Pollution Modeling and Its Application XVII}, publisher={Springer US}, author={Aneja, V. P. and Tong, Q. and Kang, D. and Ray, J. D.}, year={2007}, month={Apr}, pages={13–19} }
 @inproceedings{james_aneja_2007, title={Nitrogen emissions from agricultural sources}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84933527128&partnerID=MN8TOARS}, booktitle={100th Annual Conference and Exhibition of the Air and Waste Management Association 2007, ACE 2007}, author={James, K.M. and Aneja, V.P.}, year={2007}, pages={2469–2476} }
 @article{baek_koziel_aneja_2006, title={A preliminary review of gas-to-particle conversion monitoring and modelling efforts in the USA}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746241980&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010155}, abstractNote={Ammonia and inorganic acid gases emitted from livestock and poultry operations, manure treatment, handling and application can affect air quality by the formation of secondary fine particles. The process of gas-to-particle conversion (GTPC) of relatively short-lived gaseous ammonia to more persistent fine particles can affect local and regional air quality far away from the agricultural sources. This study focused on understanding the phenomenon and related problems of the GTPC process between ammonia, acid gases and fine particles in the atmosphere. We discuss the knowledge of PM measurement technologies with their uncertainties and introduce the most recent aerosol models available developed to simulate the equilibrium partitioning of inorganic compounds between the gas and aerosol phases. We discuss the development and evaluate progress on ambient PM research using 3D air quality models and demonstrate the importance of the GTPC process concerning the contribution of ammonia on fine PM formation in agricultural areas.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Baek, B.-H. and Koziel, J.A. and Aneja, V.P.}, year={2006}, pages={204–230} }
 @article{aneja_niyogi_roelle_2006, title={An integrated perspective on assessing agricultural air quality}, volume={6}, ISBN={1466-6650}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746227332&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010146}, abstractNote={The biogeochemical cycling of trace gases (e.g. nitrogen, sulphur, etc.), and contaminants on local, regional, and global scales is a complex system of emissions, transformations, transport, and deposition. To date, limited, if any, attempt has been made on quantifying and identifying direct emissions of gaseous sulphur compounds from agricultural operations. This represents a major regulatory need for sound and prudent environmental practice. In this paper, we summarise an integrated assessment framework for studying the agricultural air quality issues by discussing the various components of the research, education and outreach involved.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Aneja, Viney and Niyogi, D. and Roelle, P.A.}, year={2006}, pages={137–148} }
 @inproceedings{krishnan_wu_hamilton_zhang_aneja_2006, title={Application and evaluation of MM5 for North Carolina with a 4-km horizontal grid spacing}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77949293374&partnerID=MN8TOARS}, booktitle={86th AMS Annual Meeting}, author={Krishnan, S. and Wu, S.-Y. and Hamilton, D. and Zhang, Y. and Aneja, V.P.}, year={2006} }
 @article{aneja_wang_tong_kimball_steger_2006, title={Characterization of major chemical components.of fine. particulate matter in North Carolina}, volume={56}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33749151190&partnerID=MN8TOARS}, DOI={10.1080/10473289.2006.10464529}, abstractNote={Abstract This paper presents measurements of daily sampling of fine particulate matter (PM2.5) and its major chemical components at three urban and one rural locations in North Carolina during 2002. At both urban and rural sites, the major insoluble component of PM2.5 is organic matter, and the major soluble components are sulfate (SO4 2−), ammonium (NH4 +), and nitrate (NO3 −). NH4 + is neutralized mainly by SO4 2− rather than by NO3 −, except in winter when SO4 2− concentration is relatively low, whereas NO3 − concentration is high. The equivalent ratio of NH4 + to the sum of SO4 2− and NO3 − is <1, suggesting that SO4 2−and NO3 −are not completely neutralized by NH4 +. At both rural and urban sites, SO4 2−concentration displays a maximum in summer and a minimum in winter, whereas NO3 −displays an opposite seasonal trend. Mass ratio of NO3 − to SO4 2−is consistently <1 at all sites, suggesting that stationary source emissions may play an important role in PM2.5 formation in those areas. Organic carbon and elemental carbon are well correlated at three urban sites although they are poorly correlated at the agriculture site. Other than the daily samples, hourly samples were measured at one urban site. PM2.5 mass concen trations display a peak in early morning, and a second peak in late afternoon. Back trajectory analysis shows that air masses with lower PM2.5 mass content mainly originate from the marine environment or from a continental environment but with a strong subsidence from the upper troposphere. Air masses with high PM2.5 mass concentrations are largely from continental sources. Our study of fine particulate matter and its chemical composition in North Carolina provides crucial information that may be used to determine the efficacy of the new National Ambient Air Quality Standard (NAAQS) for PM fine. Moreover, the gas-to-particle conversion processes provide improved prediction of long-range transport of pollutants and air quality.}, number={8}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, Viney P. and Wang, Binyu and Tong, Daniel Q. and Kimball, Hoke and Steger, Joette}, year={2006}, month={Aug}, pages={1099–1107} }
 @article{niyogi_alapaty_phillips_aneja_2006, title={Considering ecological formulations for estimating deposition velocity in air quality models}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746257492&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010158}, abstractNote={A dry deposition modelling approach that includes surface feedback through photosynthesis relationships was recently developed. A canopy photosynthesis model is dynamically coupled to an atmospheric model with prognostic soil hydrology and surface energy balance. The effective surface resistance is calculated for a realistic and fully interactive estimation of gaseous deposition velocity (Vd). The model was able to correctly estimate observed ozone Vd over agricultural fields. The same model was tested for its ability to simulate ammonia Vd near an animal agricultural facility. The scheme did not reproduce the bi-directional exchange and had a much smaller range as compared to observations. The model was modified to include a simple ammonia compensation point formulation and the results were much closer to the observations. Study concludes that ecological approaches with default parameterisation and biophysical constants are convenient and effective in estimating Vd for air quality models.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Niyogi, D. and Alapaty, K. and Phillips, S. and Aneja, V.P.}, year={2006}, pages={270–284} }
 @article{aneja_blunden_claiborn_rogers_2006, title={Dynamic atmospheric chamber systems: Applications to trace gas emissions from soil and plant uptake}, volume={6}, ISBN={1466-6650}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746358849&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010157}, abstractNote={Atmospheric emissions, transport, transformation and deposition of trace gases may be simulated through chambers. The dynamic flow-through chamber system has been developed in response to a need to measure emissions of nitrogen, sulphur and carbon compounds for a variety of field applications. Oxides of nitrogen (NO, NO2, NOY) emissions have been measured from agricultural fertilised/unfertilised soils. Ammonia-nitrogen (NH3–N) and reduced organic sulphur compound emissions have been measured using this same technique across a gas-liquid and soil-atmosphere interface at swine waste treatment anaerobic storage lagoons and in agricultural fields. Similar chamber systems have also been deployed to measure the uptake of nitrogen, sulphur, ozone and hydrogen peroxide gases by crops and vegetation to examine atmospheric-biospheric interactions. Emission measurements compare well with a coupled gas-liquid transfer with chemical reaction model as well as a US Environmental Protection Agency (EPA) WATER9 model.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Aneja, Viney and Blunden, J. and Claiborn, C.S. and Rogers, H.H.}, year={2006}, pages={253–269} }
 @article{aneja_schlesinger_nyogi_jennings_gilliam_knighton_duke_blunden_krishnan_2006, title={Emerging national research needs for agricultural air quality}, volume={87}, ISSN={0096-3941}, url={http://dx.doi.org/10.1029/2006EO030001}, DOI={10.1029/2006EO030001}, abstractNote={Over the next 50 years, the Earth's human population is predicted to increase from the current 6.1 billion to more than 9 billion, creating a parallel increase in demand for agricultural commodities. Satisfying the demand for food is already driving changes in crop and livestock production methods that may have profound environmental effects. Increased consumption of animal protein in developed and developing countries, for example, has resulted in concentrated production of poultry and livestock, which has led to concentrated emissions of pollutants from these production facilities and has created regulatory concerns for agriculture. Development of land for nonagricultural uses has placed more pressure on marginal agricultural lands and has caused environmental degradation including the emission of trace gases (e.g., carbon,sulfur, and nitrogen species) into the atmosphere.}, number={3}, journal={Eos, Transactions American Geophysical Union}, publisher={American Geophysical Union (AGU)}, author={Aneja, Viney P. and Schlesinger, William H. and Nyogi, Dev and Jennings, Greg and Gilliam, Wendell and Knighton, Raymond E. and Duke, Clifford S. and Blunden, Jessica and Krishnan, Srinath}, year={2006}, pages={25} }
 @article{bajwa_aneja_arya_2006, title={Measurement and estimation of ammonia emissions from lagoon-atmosphere interface using a coupled mass transfer and chemical reactions model, and an equilibrium model}, volume={40}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33748805536&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2005.12.076}, abstractNote={Ammonia has recently gained importance for its increasing atmospheric concentrations and its role in the formation of aerosols. The anaerobic lagoon and spray method, commonly used for waste storage and disposal in confined animal feeding operations (CAFO), is a significant source of ammonia emissions. An accurate emission model for ammonia from aqueous surfaces can help in the development of emission factors. Data collected from field measurements made at hog waste lagoons in south eastern North Carolina, using the flow through dynamic chamber technique, were used to evaluate the Coupled mass transfer and Chemical reactions model and Equilibrium model developed by Aneja et al. [2001a. Measurement and modeling of ammonia emissions at waste treatment lagoon-Atmospheric Interface. Water, Air and Soil pollution: Focus 1, 177–188]. Sensitivity analysis shows that ammonia flux increases exponentially with lagoon temperature and pH, but a linear increase was observed with an increase in total ammoniacal nitrogen (TAN). Ammonia flux also shows a nonlinear increase with increasing wind speed. Observed ammonia fluxes were generally lower in the cold season than in the warm season when lagoon temperatures are higher. About 41% of the equilibrium model predictions and 43% of the Coupled model predictions are found to be within a factor of two of the observed fluxes. Several model performance statistics were used to evaluate the performance of the two models against the observed flux data. These indicate that the simpler Equilibrium model does as well as the Coupled model. The possible effects of the “artificial” environment within the chamber, which is different from that in the ambient atmospheric conditions above the open lagoon surface, on the measured fluxes are also recognized.}, number={SUPPL. 2}, journal={ATMOSPHERIC ENVIRONMENT}, author={Bajwa, Kanwardeep S. and Aneja, Viney P. and Arya, S. Pal}, year={2006}, pages={S275–S286} }
 @article{phillips_aneja_kang_arya_2006, title={Modelling and analysis of the atmospheric nitrogen deposition in North Carolina}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746218412&partnerID=MN8TOARS}, DOI={10.1016/j.ecolmodel.2005.03.026}, abstractNote={The availability of detailed environmental data, together with inexpensive and powerful computers, has fueled a rapid increase in predictive modeling of species environmental requirements and geographic distributions. For some species, detailed presence/absence occurrence data are available, allowing the use of a variety of standard statistical techniques. However, absence data are not available for most species. In this paper, we introduce the use of the maximum entropy method (Maxent) for modeling species geographic distributions with presence-only data. Maxent is a general-purpose machine learning method with a simple and precise mathematical formulation, and it has a number of aspects that make it well-suited for species distribution modeling. In order to investigate the efficacy of the method, here we perform a continental-scale case study using two Neotropical mammals: a lowland species of sloth, Bradypus variegatus, and a small montane murid rodent, Microryzomys minutus. We compared Maxent predictions with those of a commonly used presence-only modeling method, the Genetic Algorithm for Rule-Set Prediction (GARP). We made predictions on 10 random subsets of the occurrence records for both species, and then used the remaining localities for testing. Both algorithms provided reasonable estimates of the species’ range, far superior to the shaded outline maps available in field guides. All models were significantly better than random in both binomial tests of omission and receiver operating characteristic (ROC) analyses. The area under the ROC curve (AUC) was almost always higher for Maxent, indicating better discrimination of suitable versus unsuitable areas for the species. The Maxent modeling approach can be used in its present form for many applications with presence-only datasets, and merits further research and development.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Phillips, S.B. and Aneja, V.P. and Kang, D. and Arya, S.P.}, year={2006}, pages={231–252} }
 @article{tong_aneja_arya_ray_2006, title={Temporal variability and case study of high O<inf>3</inf> episodes in two southeastern US national parks}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746257498&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010159}, abstractNote={Despite a decreasing trend nationwide, eight-hour O3 concentrations in 25 of US national parks have increased by 8% during last decade. This study presents a 13-year observation of high O3 at the Great Smoky Mountains (GRSM) and Mammoth Cave (MACA) national parks, both among the 25 impacted parks. Although there is no monotonic increase, the later half witnessed three-fold exceedances than the former. O3 exceedances occurred most frequently in June at MACA, and in August or September at GRSM. High O3 episodes at MACA occurred during daytime or early evening, but exceedances at GRSM can be found in any hour. Air masses with high O3 at GRSM came from all directions, whereas those at MACA are predominantly from the southwest. Case studies show that high O3 episodes at MACA are developed under clear sky, high temperature, low humidity, and weak winds traveling in a uniform anti-cyclonal pathway.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Tong, D.Q. and Aneja, V.P. and Arya, S.P. and Ray, J.D.}, year={2006}, pages={173–188} }
 @article{das_aneja_kang_2006, title={Vertical distribution of VOCs and ozone observed in suburban North Carolina}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33746185438&partnerID=MN8TOARS}, DOI={10.1504/ijgenvi.2006.010147}, abstractNote={As a continuing effort by the State of North Carolina to develop a State Implementation Plan for ozone control in the Raleigh Metropolitan Statistical Area, vertical measurements of C2–C10 hydrocarbons and ozone are made on a 610 meter multi-communications tower. Results signify that both long-range transport from fossil fuel combustion, petroleum exploration, petroleum refineries, and geogenic natural gas and local emissions from surface coating and paper production are the major sources of anthropogenic organic compounds at this location. Vertical distributions of various compounds are examined with respect to the relative abundance as well as reactivity to study the role of NMHCs in ozone production. When the concentrations of NMHCs are lower than some threshold value (60 ppbC), ozone concentrations increase with the increase of NMHC concentrations; but when NMHC concentrations are higher than 60 ppbC, ozone concentrations decrease with increase of NMHC concentrations.}, number={2-3}, journal={International Journal of Global Environmental Issues}, author={Das, M. and Aneja, V.P. and Kang, D.}, year={2006}, pages={149–172} }
 @article{o’connor_roelle_aneja_2005, title={An ozone climatology: relationship between meteorology and ozone in the Southeast USA}, volume={23}, ISSN={["1741-5101"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-18844379376&partnerID=MN8TOARS}, DOI={10.1504/IJEP.2005.006855}, abstractNote={A statistical analysis of ozone (O3) concentrations and meteorological parameters was performed to determine the relationship between meteorological changes and ambient O3 concentrations in the Southeast United States. The correlation between average daily maximum O3 concentration and various meteorological variables was analysed on a monthly basis from April through October during 1980-1994. The correlations were strongest during the summer months, particularly June, July, and August. Analysis of long term O3 concentration trends indicates increasing trends during the 1980s and decreasing trends during the early 1990s.}, number={2}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION}, author={O’Connor, J.R. and Roelle, P.A. and Aneja, Viney}, year={2005}, pages={123–139} }
 @article{blunden_aneja_lonneman_2005, title={Characterization of non-methane volatile organic compounds at swine facilities in eastern North Carolina}, volume={39}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-26844482025&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2005.03.053}, abstractNote={Samples were collected and analyzed in a field study to characterize C2–C12 volatile organic compounds (VOCs) emitted at five swine facilities in Eastern North Carolina between April 2002 and February 2003. Two sites employed conventional lagoon and field spray technologies, while three sites utilized various alternative waste treatment technologies in an effort to substantially reduce gaseous compound emissions, odor, and pathogens from these swine facilities. More than 100 compounds, including various paraffins, olefins, aromatics, ethers, alcohols, aldehydes, ketones, halogenated hydrocarbons, phenols, and sulfides were positively identified and quantified by Gas Chromatographic/Flame Ionization Detection (GC/FID) analysis and confirmed by Gas Chromatographic/Mass Spectrometry (GC/MS). GC/MS analysis of one particularly complex sample collected assisted in providing identification and retention times for 17 sulfur-type VOCs including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide as well as many other VOCs. Highest VOC concentration levels measured at each of the facilities were near the hog barn ventilation fans. Total measured VOCs at the hog barns were typically dominated by oxygenated hydrocarbons (HCs), i.e., ethanol, methanol, acetaldehyde, and acetone. These compounds, in addition to other oxygenated VOCs measured at the various sites, generally represented ∼37–73% of net total measured VOCs that were emitted from the hog barns at the various sites. Dimethyl sulfide and dimethyl disulfide, both recognized as malodorous compounds, were determined to have higher concentration levels at the barns than the background at every farm sampled with the exception of one farm during the warm sampling season.}, number={36}, journal={ATMOSPHERIC ENVIRONMENT}, author={Blunden, J and Aneja, VP and Lonneman, WA}, year={2005}, month={Nov}, pages={6707–6718} }
 @article{roelle_aneja_2005, title={Modeling of ammonia emissions from soils}, volume={22}, ISSN={["1557-9018"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-11444269556&partnerID=MN8TOARS}, DOI={10.1089/ees.2005.22.58}, abstractNote={Using a dynamic flow-through chamber system in conjunction with a Thermo Environmental 17C Chemiluminescence ammonia (NH3) analyzer, emissions from slurry-amended, that is, effluent from the lagoon (∼33 kg N ha-1) and nonamended soils were calculated at a swine farm in eastern North Carolina. The average NH3-N flux values during the period when the soils were not amended with any slurry were ∼54 ng N m-2 s-1, while the average NH3-N flux values measured immediately following the application of slurry to the soil were 1723.9 ng N m-2 s-1. An empirical model relating soil temperature to NH3 flux for nonamended soils explained over 70% of the variability in NH3 emissions; however, a similar empirical model relating soil temperature to NH3 flux for slurry-amended soils was able to explain only 39% of the variability in NH3 emissions. A mass transport model, based on physical and chemical processes to estimate NH3 emissions from recently amended soils is also presented and compared and contrasted to the empiri...}, number={1}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Roelle, PA and Aneja, VP}, year={2005}, pages={58–72} }
 @article{baek_aneja_2005, title={Observation based analysis for the determination of equilibrium time constant between ammonia, acid gases, and fine particles}, volume={23}, ISSN={["1741-5101"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-18944405808&partnerID=MN8TOARS}, DOI={10.1504/IJEP.2005.006864}, abstractNote={Experimental measurements of ammonia, acid gases, and the inorganic components of atmospheric aerosols were made at a commercial hog farm in eastern North Carolina from May 1998 to June 1999 by an annular denuder system (ADS). The ADS consisted of a cyclone separator, one diffusion denuder coated with sodium carbonate, another diffusion denuder with citric acid, and a filter pack containing Teflon and nylon filters in series. The equilibrium time constant for transfer between ammonia, acid gases, and aerosol phase of ammonium nitrate and ammonium chloride was determined based on kinetic rate constants (kN as the rate constant of ammonium nitrate aerosol: 2.04 × 10-4 m³/µmole/sec; kCl as the rate constant of ammonium chloride aerosol: 3.44 × 10-4 m³/µmole/sec) and the observed inorganic components of atmospheric aerosols. The equilibrium time constant was determined based on kinetic rate constants and the observed inorganic components of atmospheric aerosols. The equilibrium time constant has a wide range of values, with an average value of 15.26 (±10.94) minutes for ambient equilibrium time between ammonia, nitric acid gas and ammonium nitrate aerosol; and 8.22 (±6.81) minutes for ammonia, hydrochloric acid, and ammonium chloride. Significant correlations were determined between comparisons of equilibrium time constant estimates with meteorological parameters, such as ambient temperature and relative humidity. The predicted chemical compositions in the particle by EQUISOLV II Model are in good agreement with the observed chemical composition at the experimental site.}, number={3}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION}, author={Baek, BH and Aneja, VP}, year={2005}, pages={239–247} }
 @article{tong_kang_aneja_ray_2005, title={Reactive nitrogen oxides in the southeast United States national parks: source identification, origin, and process budget}, volume={39}, DOI={10.1016/j.atmonsenv.2004.09.035}, number={2}, journal={Atmospheric Environment}, author={Tong, D. Q. and Kang, D. W. and Aneja, Viney and Ray, J. D.}, year={2005}, pages={315–327} }
 @article{tong_kang_aneja_ray_2005, title={Reactive nitrogen oxides in the southeast United States national parks: source identification, origin, and process budget}, volume={39}, ISSN={1352-2310}, url={http://dx.doi.org/10.1016/j.atmosenv.2004.09.035}, DOI={10.1016/j.atmosenv.2004.09.035}, abstractNote={We present in this study both measurement-based and modeling analyses for elucidation of source attribution, influence areas, and process budget of reactive nitrogen oxides at two rural southeast United States sites (Great Smoky Mountains national park (GRSM) and Mammoth Cave national park (MACA)). Availability of nitrogen oxides is considered as the limiting factor to ozone production in these areas and the relative source contribution of reactive nitrogen oxides from point or mobile sources is important in understanding why these areas have high ozone. Using two independent observation-based techniques, multiple linear regression analysis and emission inventory analysis, we demonstrate that point sources contribute a minimum of 23% of total NOy at GRSM and 27% at MACA. The influence areas for these two sites, or origins of nitrogen oxides, are investigated using trajectory-cluster analysis. The result shows that air masses from the West and Southwest sweep over GRSM most frequently, while pollutants transported from the eastern half (i.e., East, Northeast, and Southeast) have limited influence (<10% out of all air masses) on air quality at GRSM. The processes responsible for formation and removal of reactive nitrogen oxides are investigated using a comprehensive 3-D air quality model (Multiscale Air Quality SImulation Platform (MAQSIP)). The NOy contribution associated with chemical transformations to NOz and O3, based on process budget analysis, is as follows: 32% and 84% for NOz, and 26% and 80% for O3 at GRSM and MACA, respectively. The similarity between NOz and O3 process budgets suggests a close association between nitrogen oxides and effective O3 production at these rural locations.}, number={2}, journal={Atmospheric Environment}, publisher={Elsevier BV}, author={Tong, Daniel Quansong and Kang, Daiwen and Aneja, Viney P. and Ray, John D.}, year={2005}, month={Jan}, pages={315–327} }
 @article{phillips_arya_aneja_2004, title={Ammonia flux and dry deposition velocity from near-surface concentration gradient measurements over a grass surface in North Carolina}, volume={38}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-2442425948&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2004.02.054}, abstractNote={Atmospheric ammonia concentrations were measured during fall 2001, winter, spring, and summer 2002 over natural surfaces in North Carolina where animal farms and waste storage and treatment lagoons (which are known to emit ammonia) at two heights (2 and 6 m) above the surface employing an arrangement of two Thermo Environmental Instruments, Inc. Model 17C chemiluminescent nitrogen oxides (NOX)–ammonia (NH3) analyzers along with a solenoid for each analyzer to alternate measurements between the two elevations. Simultaneously, mean winds and temperatures are also measured at the same two heights. The micrometeorological gradient method is used in conjunction with the Monin–Obukhov similarity theory, to estimate the vertical flux and dry deposition velocity of ammonia under different meteorological conditions. Diurnal and seasonal variations of ammonia flux and dry deposition velocity were investigated under a wide range of wind and atmospheric stability conditions yielding hourly variation of NH3 fluxes and deposition during each seasonal campaign. Fall average NH3 concentrations were generally the highest with daytime concentrations of 7.60±6.54 μg m−3 at 2 m, while nighttime NH3 concentrations were 7.25±6.14 μg m−3 at 2 m. The winter season had the lowest overall concentrations collected during each seasonal campaign with averages of 1.73±2.00 μg m−3 (2 m) during daytime and 1.37±1.50 μg m−3 (2 m) during nighttime. Deposition and emission occur, both on daily and seasonal scales. Summer measurements yielded the largest average daytime deposition velocity of 3.94±2.79 cm s−1, whereas winter measurements gave the lowest daytime velocities with an average of 2.41±1.92 cm s−1. The largest nighttime deposition velocities were estimated during the summer season with an average of 0.76±1.69 cm s−1, whereas fall nighttime deposition velocities were considerably lower at 0.07±0.17 cm s−1. Regression relationships between the ammonia deposition velocity and the friction velocity are obtained for different stability conditions.}, number={21}, journal={ATMOSPHERIC ENVIRONMENT}, author={Phillips, SB and Arya, SP and Aneja, VP}, year={2004}, month={Jul}, pages={3469–3480} }
 @inproceedings{blunden_aneja_lonneman_2004, title={Characterization of non-methane volatile organic compounds at swine facilities in Eastern North Carolina}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-19944375455&partnerID=MN8TOARS}, booktitle={Symposium on Air Quality Measurement Methods and Technology 2004}, author={Blunden, J. and Aneja, V.P. and Lonneman, W.A.}, year={2004}, pages={907–920} }
 @article{baek_aneja_tong_2004, title={Chemical coupling between ammonia, acid gases, and fine particles}, volume={129}, ISSN={["1873-6424"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1642422761&partnerID=MN8TOARS}, DOI={10.1016/j.envpol.2003.09.022}, abstractNote={The concentrations of inorganic aerosol components in the fine particulate matter (PM(fine)< or =2.5 microm) consisted of primarily ammonium, sodium, sulfate, nitrate, and chloride are related to the transfer time scale between gas to particle phase, which is a function of the ambient temperature, relative humidity, and their gas phase constituent concentrations in the atmosphere. This study involved understanding the magnitude of major ammonia sources; and an up-wind and down-wind (receptor) ammonia, acid gases, and fine particulate measurements; with a view to accretion gas-to-particle conversion (GTPS) process in an agricultural/rural environment. The observational based analysis of ammonia, acid gases, and fine particles by annular denuder system (ADS) coupled with a Gaussian dispersion model provided the mean pseudo-first-order k(S-1) between NH(3) and H(2)SO(4) aerosol approximately 5.00 (+/-3.77)x10(-3) s(-1). The rate constant was found to increase as ambient temperature, wind speed, and solar radiation increases, and decreases with increasing relative humidity. The observed [NH(3)][HNO(3)] products exceeded values predicted by theoretical equilibrium constants, due to a local excess of ammonia concentration.}, number={1}, journal={ENVIRONMENTAL POLLUTION}, author={Baek, BH and Aneja, VP and Tong, QS}, year={2004}, month={May}, pages={89–98} }
 @article{baek_aneja_2004, title={Measurement and analysis of the relationship between ammonia, acid gases, and fine particles in eastern North Carolina}, volume={54}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-2142828493&partnerID=MN8TOARS}, DOI={10.1080/10473289.2004.10470933}, abstractNote={Abstract An annular denuder system, which consisted of a cyclone separator; two diffusion denuders coated with sodium carbonate and citric acid, respectively; and a filter pack consisting of Teflon and nylon filters in series, was used to measure acid gases, ammonia (NH3), and fine particles in the atmosphere from April 1998 to March 1999 in eastern North Carolina (i.e., an NH3−rich environment). The sodium carbonate denuders yielded average acid gas concentrations of 0.23 μg/m3 hydrochloric acid (standard deviation [SD] ± 0.2 μg/m3); 1.14 μg/m3 nitric acid (SD ± 0.81 μg/m3), and 1.61 μg/m3 sulfuric acid (SD ± 1.58 μg/m3). The citric acid denuders yielded an average concentration of 17.89 μg/m3 NH3 (SD ± 15.03 μg/m3). The filters yielded average fine aerosol concentrations of 1.64 μg/m3 ammonium (NH4 +;SD ± 1.26 μg/m3); 0.26 μg/m3 chloride (SD ± 0.69 μg/m3), 1.92 μg/m3 nitrate (SD ± 1.09 μg/m3), and 3.18 μg/m3 sulfate (SO4 2−; SD ± 3.12 μg/m3). From seasonal variation, the measured particulates (NH4 +,SO4 2−, and nitrate) showed larger peak concentrations during summer, suggesting that the gas-to-particle conversion was efficient during summer. The aerosol fraction in this study area indicated the domination of ammonium sulfate particles because of the local abundance of NH3, and the long-range transport of SO4 2− based on back trajectory analysis. Relative humidity effects on gas-to-particle conversion processes were analyzed by particulate NH4 + concentration originally formed from the neutralization processes with the secondary pollutants in the atmosphere.}, number={5}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Baek, BH and Aneja, VP}, year={2004}, month={May}, pages={623–633} }
 @inproceedings{phillips_arya_aneja_2004, title={Measurement and modeling of ammonia flux and deposition velocity over natural surfaces in Eastern North Carolina}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-22144469849&partnerID=MN8TOARS}, booktitle={13th Joint Conference on the Applications of Air Pollution Meteorology with the Air and Waste Management Association}, author={Phillips, S.B. and Arya, S.P. and Aneja, V.P.}, year={2004}, pages={199–202} }
 @inbook{kang_aneja_mathur_ray_2004, title={Measurements and Modeling of Regional Air Quality in three Southeast United States National Parks}, ISBN={9781461346975 9781441988676}, url={http://dx.doi.org/10.1007/978-1-4419-8867-6_5}, DOI={10.1007/978-1-4419-8867-6_5}, booktitle={Air Pollution Modeling and Its Application XVI}, publisher={Springer US}, author={Kang, Daiwen and Aneja, Viney P. and Mathur, Rohit and Ray, John D.}, year={2004}, pages={57–65} }
 @article{kang_aneja_das_seila_2004, title={Measurements of air-surface exchange rates of volatile organic compounds}, volume={22}, ISSN={["0957-4352"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-11244260492&partnerID=MN8TOARS}, DOI={10.1504/IJEP.2004.005909}, abstractNote={Vertical gradients of volatile organic compounds (VOCs) were measured over a maize field and a soybean field in 1995 and 1996, respectively, in the Lower Coastal Plains of North Carolina. The measurements over the maize field were conducted in its early growth period, during May 1995, and the measurements over the soybean field were conducted in its middle and later growth periods during July through August 1996 at the same location. These measurements were combined with micrometeorological flux measurements to determine emission flux measurements for various VOCs. This measurement programme was part of project NOVA (Natural emissions of Oxidant precursors: Validation of techniques and Assessment) to estimate the flux of VOCs. Methanol was identified as the major biogenic compound for both years with the average flux of 3450 ± 1456 µg/m²/hr over maize and 3079 ± 2766 µg/m²/hr over soybean. Acetone is another compound that was identified as a biogenic compound for both years with the average flux of 425 ± 223 µg/m²/hr over maize and 2701 ± 1710 µg/m²/hr over soybean. In addition to biogenic compounds, a large number of aromatic compounds, including styrene and 1,2,4-trimethylbenzene, were also identified as emissions from the ground over the soybean field.}, number={5}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION}, author={Kang, D and Aneja, VP and Das, M and Seila, R}, year={2004}, pages={547–562} }
 @article{kang_aneja_mathur_ray_2004, title={Observed and modeled VOC chemistry under high VOC/NOx conditions in the Southeast United States national parks}, volume={38}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4043070651&partnerID=MN8TOARS}, DOI={10.1016/j.atmosenv.2004.05.054}, abstractNote={In airsheds that contain high volatile organic compounds (VOCs) and low NOx (=NO+NO2) concentrations, ozone (O3) production may be significantly suppressed by NOx reactions that lead to the formation of organic nitrates. O3 and its precursors (VOCs and NOx) ambient levels simulated using a regional-scale photochemical model, called Multiscale Air Quality Simulation Platform, are analyzed and compared to observed data from three southeast United States national parks.}, number={29}, journal={ATMOSPHERIC ENVIRONMENT}, author={Kang, DW and Aneja, VP and Mathur, R and Ray, JD}, year={2004}, month={Sep}, pages={4969–4974} }
 @article{aneja_brittig_kim_hanna_2004, title={Ozone and other air quality-related variables affecting visibility in the southeast United States}, volume={54}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-2942525221&partnerID=MN8TOARS}, DOI={10.1080/10473289.2004.10470939}, abstractNote={Abstract An analysis of ozone (O3) concentrations and several other air quality-related variables was performed to elucidate their relationship with visibility at five urban and semi-urban locations in the southeast United States during the summer seasons of 1980-1996. The role and impact of O3 on aerosols was investigated to ascertain a relationship with visibility. Regional trend analysis over the 1980s reveals an increase in maximum O3 concentration coupled with a decrease in visibility. However, a similar analysis for the 1990s shows a leveling-off of both O3 and visibility; in both cases, the results were not statistically significant at the 5% level. A case study of site-specific trends at Nashville, TN, followed similar trends. To better understand the relationships between O3 concentration and visibility, the analysis was varied from yearly through daily to hourly averaged values. This increased temporal resolution showed a statistically significant inverse relationship between visibility and O3. Site-specific hourly r2 values ranged from 0.02 to 0.43. Additionally, by performing back-trajectory analysis, it was found that the visibility degraded by air mass migration over polluted areas.}, number={6}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, VP and Brittig, JS and Kim, DS and Hanna, A}, year={2004}, month={Jun}, pages={681–688} }
 @article{aneja_nelson_roelle_walker_battye_2003, title={Agricultural ammonia emissions and ammonium concentrations associated with aerosols and precipitation in the southeast United States}, volume={108}, ISSN={["2169-8996"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1642562702&partnerID=MN8TOARS}, DOI={10.1029/2002jd002271}, abstractNote={[1] Temporal and spatial variations in ammonia (NH3) emissions and ammonium (NH4+) concentrations associated with aerosols and volume-weighted NH4+ concentration in precipitation are investigated over the period 1990–1998 in the southeast United States (Alabama, Florida, Georgia, Kentucky, North Carolina, South Carolina, Mississippi, and Tennessee). These variations were analyzed using an NH3 emissions inventory developed for the southeast United States and ambient NH4+ data from the various Clean Air Status and Trends Network (CASTNet) and the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Results show that natural log-transformed annual NH4+ concentration associated with aerosols increases with natural log-transformed annual NH3 emission density within the same county (R2 = 0.86, p < 0.0001, N = 12). Natural log-transformed annual volume-weighted average NH4+ concentration in precipitation shows only a very weak positive correlation with natural log-transformed annual NH3 emission densities within the corresponding county (R2 = 0.12, p = 0.04, N = 29). Analysis of NH4+ concentration associated with aerosols at CASTNet sites revealed that temperature, precipitation amount, and relative humidity are the most statistically significant (p < 0.05) parameters in predicting the weekly concentrations of NH4+ during the period 1990–1998. Wind speed and wind direction were also statistically significant (p < 0.05) at several CASTNet sites, but the results were less consistent. Investigation into wet NH4+ concentration in precipitation consistently yielded temperature as a statistically significant (p < 0.05) parameter at individual sites. Trends over the period 1990–1998 revealed a slight decrease in NH4+ concentration at CASTNet site SPD, Claiborne County, Tennessee (2.14–1.88 μg m−3), while positive trends in NH4+ concentration in precipitation were evident at NADP sites NC35, Sampson County, North Carolina (0.2–0.48 mg L−1) and KY35, Rowan County, Kentucky (0.2–0.35 mg L−1) over the period 1990–1998.}, number={D4}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Aneja, VP and Nelson, DR and Roelle, PA and Walker, JT and Battye, W}, year={2003}, month={Feb} }
 @article{sutton_asman_ellermann_van jaarsveld_acker_aneja_duyzer_horvath_paramonov_mitosinkova_et al._2003, title={Establishing the link between ammonia emission control and measurements of reduced nitrogen concentrations and deposition}, volume={82}, ISSN={["1573-2959"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-12244275034&partnerID=MN8TOARS}, DOI={10.1023/A:1021834132138}, number={2}, journal={ENVIRONMENTAL MONITORING AND ASSESSMENT}, author={Sutton, MA and Asman, WAH and Ellermann, T and Van Jaarsveld, JA and Acker, K and Aneja, V and Duyzer, J and Horvath, L and Paramonov, S and Mitosinkova, M and et al.}, year={2003}, month={Mar}, pages={149–185} }
 @article{battye_aneja_roelle_2003, title={Evaluation and improvement of ammonia emissions inventories}, volume={37}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0042167618&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(03)00343-1}, abstractNote={Two case studies are performed to improve ammonia emissions inputs used to model fine particulate matter (PM2.5 is the portion of particulate matter smaller than 2.5 μm aerodynamic diameter) formation of ammonium sulfate and ammonium nitrate. Ammonia emissions are analyzed in detail for North Carolina and the San Joaquin Valley (SJV) of California, with a focus on the Charlotte, NC, and Fresno, California metropolitan areas. A new gridded ammonia emissions inventories suitable for atmospheric modeling for the two case study cities was also developed. Agricultural sources accounted for the bulk of ammonia emissions in both case studies. Livestock waste contributed about 80% in North Carolina and 64% in the SJV, while fertilizer application contributed about 6–7% in both domains. Forests and non-agricultural vegetation contributed 5% in North Carolina and 12% in the SJV. Motor vehicles accounted for about 6% of ammonia emissions in North Carolina and 14% in the SJV. In the Charlotte and Fresno urban areas, the distribution of emissions is less heavily weighted toward agricultural sources and more heavily weighted toward highway vehicles (highway vehicles account for an estimated 64% of emissions in Charlotte and 51% of emissions in Fresno). The emissions estimates for agricultural sources (livestock and fertilizer application) decline to approximately 14% in the winter for both the Charlotte and Fresno urban areas. Emissions estimates for soils and vegetation also decline to approximately 0 during the winter for both the Fresno and Charlotte area. As a result, motor vehicles account for a larger fraction (approximately 73% and 70% for Charlotte and Fresno, respectively) of winter ammonia emissions, particularly in the Charlotte urban area.}, number={27}, journal={ATMOSPHERIC ENVIRONMENT}, author={Battye, W and Aneja, VP and Roelle, PA}, year={2003}, month={Sep}, pages={3873–3883} }
 @article{das_kang_aneja_lonneman_cook_wesely_2003, title={Measurements of hydrocarbon air-surface exchange rates over maize}, volume={37}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037403349&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(03)00076-1}, abstractNote={Vertical gradients of volatile organic compounds (VOCs) were measured over a maize (Zea mays) field, in its early growth period, during May 1995, in the Lower Coastal Plains of North Carolina. These measurements were combined with micrometeorological flux measurements to determine emission flux measurements for various VOCs. This measurement program was part of project NOVA (Natural emissions of Oxidant precursors: Validation of techniques and Assessment) to estimate the flux of VOCs. Average emissions of VOCs (and standard error) was estimated to be 4900±700 μg/m2/h out of which emission for methanol averaged (3450±420) μg/m2/h. A methanol emission rate of 35 μg/g/h was calculated for maize from the estimated emission of methanol and biomass density for the site.}, number={16}, journal={ATMOSPHERIC ENVIRONMENT}, author={Das, M and Kang, DW and Aneja, VP and Lonneman, W and Cook, DR and Wesely, ML}, year={2003}, month={May}, pages={2269–2277} }
 @article{kang_aneja_mathur_ray_2003, title={Nonmethane hydrocarbons and ozone in three rural southeast United States national parks: A model sensitivity analysis and comparison to measurements}, volume={108}, ISSN={["2169-8996"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0347692888&partnerID=MN8TOARS}, DOI={10.1029/2002jd003054}, abstractNote={[1] A detailed modeling analysis is conducted focusing on nonmethane hydrocarbons and ozone in three southeast United States national parks for a 15-day time period (14–29 July 1995) characterized by high O3 surface concentrations. The three national parks are Smoky Mountains National Park (GRSM), Mammoth Cave National Park (MACA), and Shenandoah National Park (SHEN), Big Meadows. A base emission scenario and eight variant predictions are analyzed, and predictions are compared with data observed at the three locations for the same time period. Model-predicted concentrations are higher than observed values for O3 (with a cutoff of 40 ppbv) by 3.0% at GRSM, 19.1% at MACA, and 9.0% at SHEN (mean normalized bias error). They are very similar to observations for overall mean ozone concentrations at GRSM and SHEN. They generally agree (the same order of magnitude) with observed values for lumped paraffin compounds but are an order of magnitude lower for other species (isoprene, ethene, surrogate olefin, surrogate toluene, and surrogate xylene). Model sensitivity analyses here indicate that each location differs in terms of volatile organic compound (VOC) capacity to produce O3, but a maximum VOC capacity point (MVCP) exists at all locations that changes the influence of VOCs on O3 from net production to production suppression. Analysis of individual model processes shows that more than 50% of daytime O3 concentrations at the high-elevation rural locations (GRSM and SHEN) are transported from other areas; local chemistry is the second largest O3 contributor. At the low-elevation location (MACA), about 80% of daytime O3 is produced by local chemistry and 20% is transported from other areas. Local emissions (67–95%) are predominantly responsible for VOCs at all locations, the rest coming from transport. Chemistry processes are responsible for about 50% removal of VOCs for all locations; less than 10% are lost to surface deposition and the rest are exported to other areas. Metrics, such as VOC potential for O3 production (VPOP), which links the chemistry processes of both O3 and VOCs and MVCP, are devised to measure the different characteristics of O3 production and VOCs. The values of the defined metrics are mapped for the entire modeling domain. Implications of this model exercise in understanding O3 production are analyzed and discussed. Even though this study was focused on three United States national parks, the research results and conclusions may be applicable to other or to similar rural environments in the southeast United States.}, number={D19}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Kang, DW and Aneja, VP and Mathur, R and Ray, JD}, year={2003}, month={Oct} }
 @article{das_aneja_2003, title={Regional analysis of nonmethane volatile organic compounds in the Lower Troposphere of the Southeast United States}, volume={129}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0346749358&partnerID=MN8TOARS}, DOI={10.1061/(asce)0733-9372(2003)129:12(1085)}, abstractNote={Nonmethane organic compounds (NMOCs) along with ozone as well as other trace gas and meteorological parameters were measured at eight rural sites located in the Southeast United States, as part of the Southern Oxidants Study. Fifty-four C2C10 NMOCs were collected from 1,2001,300 local time, once every six days from September 1992 through October 1993 and intermittently during 1994. This study was undertaken to characterize the nonmethane hydrocarbons in the rural areas of Southeast United States with respect to their concentrations, reactivities, and relative importance of natural and anthropogenic abundances of NMOCs. Though the sites are well removed from large urban source regions, the observations show a clear anthropogenic influence on the hydrocarbon levels at these rural sites. The data for the sites show similar seasonal patterns for total NMOC with summer maxima (average concentrations of 198 ppbC at the Long Creek, South Carolina, site to 47 ppbC at the Candor, North Carolina site) and fall minima (average concentrations of 73 ppbC at the Long Creek site to 31 ppbC at the Centreville, Alabama site). A secondary maximum is observed during the winter. A seasonal trend was observed in the concentrations of light molecular weight C\d2–C\d4 NMOCs (ethane, ethene, acetylene, propane, \ii-butane, and \in-butane) with a winter maximum and a summer minimum. An analysis of changes in C\d2–C\d4 hydrocarbon ratios over a period of one year indicates that the variation is most likely due to seasonal changes in OH concentrations. A seasonal trend was also observed for the biogenically emitted NMOC, isoprene, with summer maxima (average concentrations of 37 ppbC at the Long Creek, South Carolina, site to 8.6 ppbC at the Giles County, Tennessee and Metter, Georgia, sites) and winter minima with winter seasonal values below the level of detection. Isoprene was observed to be the most dominant NMOC at most sites during the summer. The ambient concentrations of isoprene measured during the summer were found to be dependent on the ambient temperature. The monoterpenes \ia-pinene, \ib-pinene, and \id-limonene also peaked during the summer with averages ranging between 3.19 ppbC (Centreville, Alabama) and 6.38 ppbC (Oak Grove, Missouri), and a background concentration of 1.25 to 1.9 ppbC for all the sites during the winter.}, number={12}, journal={Journal of Environmental Engineering}, author={Das, M. and Aneja, Viney}, year={2003}, pages={1085–1103} }
 @article{roelle_aneja_2002, title={Characterization of ammonia emissions from soils in the upper coastal plain, North Carolina}, volume={36}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036150359&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(01)00355-7}, abstractNote={A dynamic flow-through chamber system was used to measure fluxes of ammonia-nitrogen (NH3-N, where NH3-N=(14/17)NH3) from soil surfaces. The research site was located in eastern North Carolina (35.9°N latitude; 77.7°W longitude) and measurements were conducted during spring and winter 2000, in order to assess the NH3 source strength of intensively managed agricultural soils and the physiochemical properties which control these emissions. Soil temperature (Tsoil), soil pH, soil moisture, total Kjeldahl nitrogen (TKN=organic N+NH3-N+NH4+-N) were monitored throughout both research periods. Soil temperature was found to explain the largest variability in soil NH3 emissions (Log10 NH3-N Flux=0.054Tsoil+0.66; R2=0.71), suggesting that an approach similar in design to the biogenic emissions inventory system land use and temperature model for NO emissions, might be effective for modeling biogenic NH3 emissions. Soil nitrogen was also significant in predicting NH3 flux [NH3 Flux=55.5(NH3-N)−160, R2=0.86; NH3 Flux=0.6(TKN)−410, R2=0.27], but only after the two days with the heaviest rainfall were removed from the regression, emphasizing the role of soil moisture in controlling the transfer of gases across the soil/air interface. Soil pH remained relatively constant throughout both research periods and therefore did not serve as a useful predictor of NH3 flux. A rain event, followed by a drying period produced a characteristic pulse in ammonia emissions. This pulsing phenomenon has been observed for other trace gases by various researchers. This research location was the site of a commercial hog operation, which allowed for the comparison of soil and lagoon emissions (lagoon emissions were based on an algorithm developed by Aneja et al. (J. Geophys. Res. 105 (2000) 11,535). An analysis of the source strengths confirmed that lagoon emissions are a larger flux source (average lagoon flux ∼18,137 ng N m−2 s−1; average soil flux ∼54 ng N m−2 s−1); however soil surfaces make up a larger fraction of a commercial hog operation than the lagoon surfaces, and as a result they cannot be neglected when developing and apportioning NH3 emissions. A yearly average of ammonia emissions at this site revealed that soil emissions represent approximately 28% of the lagoon emissions.}, number={6}, journal={ATMOSPHERIC ENVIRONMENT}, author={Roelle, PA and Aneja, VP}, year={2002}, month={Feb}, pages={1087–1097} }
 @article{roelle_aneja_mathur_vukovich_peirce_2002, title={Modeling nitric oxide emissions from biosolid amended soils}, volume={36}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036888563&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(02)00655-6}, abstractNote={Utilizing a state-of-the-art mobile laboratory in conjunction with a dynamic flow-through chamber system, nitric oxide concentrations [NO] were measured and NO fluxes were calculated during the summer, winter and spring of 1999/2000. The field site where these measurements were conducted was an agricultural soil amended with biosolids from a municipal wastewater treatment facility. These NO flux values were then used to assess the impact of including biosolid amended soils as a land-use class in an air quality model. The average NO flux from this biosolid amended soil was found to be exponentially dependent on soil temperature [NO Flux (ngNm−2s−1)=1.07exp(0.14Tsoil); R2=0.81—NO Flux=71.3ngNm−2s−1 at 30°C]. Comparing this relationship to results of the widely applied biogenic emissions inventory system (BEIS2) model revealed that for this field site, if the BEIS2 model was used, the NO emissions would have been underestimated by a factor of 26. Using this newly developed NO flux algorithm, combined with North Carolina Division of Water Quality statistics on how many biosolid amended acres are permitted per county, county-based NO inventories from these biosolid amended soils were calculated. Results from this study indicate that county-level biogenic NO emissions can increase by as much as 18% when biosolid amended soils are included as a land-use class. The multiscale air quality simulation platform (MAQSIP) was then used to determine differences in ozone (O3) and odd-reactive nitrogen compounds (NOy) between models run with and without the biosolid amended acreages included in the inventory. Results showed that during the daytime, when atmospheric mixing heights are typically at their greatest, any increase in O3 or NOy concentrations predicted by the model were small (<3%). In some locations during late evening/early morning hours, ozone was found to be consumed by as much as 11%.}, number={36-37}, journal={ATMOSPHERIC ENVIRONMENT}, author={Roelle, PA and Aneja, VP and Mathur, R and Vukovich, J and Peirce, J}, year={2002}, month={Dec}, pages={5687–5696} }
 @article{roelle_aneja_2002, title={Nitric oxide emissions from soils amended with municipal waste biosolids}, volume={36}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036136766&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(01)00415-0}, abstractNote={Land spreading nitrogen-rich municipal waste biosolids (NO3 -No256 mg N kg � 1 dry weight, NH3-NB23,080 mg Nk g � 1 dry weight, Total Kjeldahl NB41,700 mg N kg � 1 dry weight) to human food and non-food chain land is a practice followed throughout the US. This practice may lead to the recovery and utilization of the nitrogen by vegetation, but it may also lead to emissions of biogenic nitric oxide (NO), which may enhance ozone pollution in the lower levels of the troposphere. Recent global estimates of biogenic NO emissions from soils are cited in the literature, which are based on field measurements of NO emissions from various agricultural and non-agricultural fields. However, biogenic emissions of NO from soils amended with biosolids are lacking. Utilizing a state-of-the-art mobile laboratory and a dynamic flow-through chamber system, in-situ concentrations of nitric oxide (NO) were measured during the spring/summer of 1999 and winter/spring of 2000 from an agricultural soil which is routinely amended with municipal waste biosolids. The average NO flux for the late spring/summer time period (10 June 1999–5 August 1999) was 69.4734.9 ng N m � 2 s � 1 . Biosolids were applied during September 1999 and the field site was sampled again during winter/spring 2000 (28 February 2000–9 March 2000), during which the average flux was 3.671.7 ng N m � 2 s � 1 . The same field site was sampled again in late spring (2–9 June 2000) and the average flux was 64.8741.0 ng N m � 2 s � 1 .A n observationally based model, developed as part of this study, found that summer accounted for 60% of the yearly emission while fall, winter and spring accounted for 20%, 4% and 16% respectively. Field experiments were conducted which indicated that the application of biosolids increases the emissions of NO and that techniques to estimate biogenic NO emissions would, on a yearly average, underestimate the NO flux from this field by a factor of 26. Soil temperature and % water filled pore space (%WFPS) were observed to be significant variables for predicting NO emissions, however %WFPS was found to be most significant during high soil temperature conditions. In the range of pH values found at this site (5.870.3), pH was not observed to be a significant parameter in predicting NO emissions. r 2002 Elsevier Science Ltd. All rights reserved.}, number={1}, journal={ATMOSPHERIC ENVIRONMENT}, author={Roelle, PA and Aneja, VP}, year={2002}, month={Jan}, pages={137–147} }
 @article{tabachow_roelle_peirce_aneja_2002, title={Soil nitric oxide emissions: Lab and field measurements and comparison}, volume={19}, ISSN={["1092-8758"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0242488928&partnerID=MN8TOARS}, DOI={10.1089/109287502760271526}, abstractNote={Equipment and procedures are developed and implemented to measure nitric oxide (NO) emissions from unamended and municipal wastewater treatment plant biosolids-amended soil in controlled laboratory...}, number={4}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Tabachow, RM and Roelle, PA and Peirce, JJ and Aneja, VP}, year={2002}, pages={205–214} }
 @article{mohamed_kang_aneja_2002, title={Volatile organic compounds in some urban locations in United States}, volume={47}, ISSN={["0045-6535"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036595008&partnerID=MN8TOARS}, DOI={10.1016/S0045-6535(02)00107-8}, abstractNote={Volatile organic compounds (VOCs) have been determined to be human risk factors in urban environments, as well as primary contributors to the formation of photochemical oxidants. Ambient air quality measurements of 54 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in or near 13 urban locations in the United States during September 1996 to August 1997. Air samples were collected and analyzed in accordance with US Environmental Protection Agency-approved methods. The target compounds most commonly found were benzene, toluene, xylene and ethylbenzene. These aromatic compounds were highly correlated and proportionally related in a manner suggesting that the primary contributors were mobile sources in all the urban locations studied. Concentrations of total hydrocarbons ranged between 1.39 and 11.93 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations, and no single factor seemed to explain trends for this group of compounds. The highest halogenated hydrocarbon concentrations ranged from 0.24 ppbv for methylene chloride to 1.22 ppbv for chloromethane. At participating urban locations for the year of data considered, levels of carbonyls were higher than the level of the other organic compound groups, suggesting that emissions from motor vehicles and photochemical reactions strongly influence ambient air concentrations of carbonyls. Of the most prevalent carbonyls, formaldehyde and acetaldehyde were the dominant compounds, ranging from 1.5-7.4 ppbv for formaldehyde, to 0.8-2.7 ppbv for acetaldehyde.}, number={8}, journal={CHEMOSPHERE}, author={Mohamed, MF and Kang, DW and Aneja, VP}, year={2002}, month={Jun}, pages={863–882} }
 @article{aneja_roelle_murray_southerland_erisman_fowler_asman_patni_2001, title={Atmospheric nitrogen compounds II: emissions, transport, transformation, deposition and assessment}, volume={35}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034744409&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(00)00543-4}, abstractNote={The Atmospheric Nitrogen Compounds II: Emissions, Transport, Transformation, Deposition and Assessment workshop was held in Chapel Hill, NC from 7 to 9 June 1999. This international conference, which served as a follow-up to the workshop held in March 1997, was sponsored by: North Carolina Department of Environment and Natural Resources; North Carolina Department of Health and Human Services, North Carolina Office of the State Health Director; Mid-Atlantic Regional Air Management Association; North Carolina Water Resources Research Institute; Air and Waste Management Association, RTP Chapter; the US Environmental Protection Agency and the North Carolina State University (College of Physical and Mathematical Sciences, and North Carolina Agricultural Research Service). The workshop was structured as an open forum at which scientists, policy makers, industry representatives and others could freely share current knowledge and ideas, and included international perspectives. The workshop commenced with international perspectives from the United States, Canada, United Kingdom, the Netherlands, and Denmark. This article summarizes the findings of the workshop and articulates future research needs and ways to address nitrogen/ammonia from intensively managed animal agriculture. The need for developing sustainable solutions for managing the animal waste problem is vital for shaping the future of North Carolina. As part of that process, all aspects of environmental issues (air, water, soil) must be addressed as part of a comprehensive and long-term strategy. There is an urgent need for North Carolina policy makers to create a new, independent organization that will build consensus and mobilize resources to find technologically and economically feasible solutions to this aspect of the animal waste problem.}, number={11}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, VP and Roelle, PA and Murray, GC and Southerland, J and Erisman, JW and Fowler, D and Asman, WAH and Patni, N}, year={2001}, pages={1903–1911} }
 @article{roelle_aneja_gay_geron_pierce_2001, title={Biogenic nitric oxide emissions from cropland soils}, volume={35}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035238856&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(00)00279-X}, abstractNote={Emissions of nitric oxide (NO) were determined during late spring and summer 1995 and the spring of 1996 from four agricultural soils on which four different crops were grown. These agricultural soils were located at four different sites throughout North Carolina. Emission rates were calculated using a dynamic flow-through chamber system coupled to a mobile laboratory for in-situ analysis. Average NO fluxes during late spring 1995 were: 50.9±47.7 ng N m−2 s−1 from soil planted with corn in the lower coastal plain. Average NO fluxes during summer 1995 were: 6.4±4.6 and 20.2±19.0 ng N m−2 s−1, respectively, from soils planted with corn and soybean in the coastal region; 4.2±1.7 ng N m−2 s−1 from soils planted with tobacco in the piedmont region; and 8.5±4.9 ng N m−2 s−1 from soils planted with corn in the upper piedmont region. Average NO fluxes for spring 1996 were: 66.7±60.7 ng N m−2 s−1 from soils planted with wheat in the lower coastal plain; 9.5±2.9 ng N m−2 s−1 from soils planted with wheat in the coastal plain; 2.7±3.4 ng N m−2 s−1 from soils planted with wheat in the piedmont region; and 56.1±53.7 ng N m−2 s−1 from soils planted with corn in the upper piedmont region. An apparent increase in NO flux with soil temperature was present at all of the locations. The composite data from all the research sites revealed a general positive trend of increasing NO flux with soil water content. In general, increases in total extractable nitrogen (TEN) appeared to be related to increased NO emissions within each site, however a consistent trend was not evident across all sites.}, number={1}, journal={ATMOSPHERIC ENVIRONMENT}, author={Roelle, PA and Aneja, VP and Gay, B and Geron, C and Pierce, T}, year={2001}, pages={115–124} }
 @article{aneja_roelle_li_2001, title={Effect of environmental variables on NO emissions from agricultural soils}, volume={41}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035521253&partnerID=MN8TOARS}, number={3}, journal={Phyton - Annales Rei Botanicae}, author={Aneja, V.P. and Roelle, P.A. and Li, Y.}, year={2001}, pages={29–40} }
 @article{aneja_bunton_walker_malik_2001, title={Measurement and analysis of atmospheric ammonia emissions from anaerobic lagoons}, volume={35}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035126691&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(00)00547-1}, abstractNote={Ammonia-nitrogen flux (NH3-N=(14/17)NH3) was determined from six anaerobic swine waste storage and treatment lagoons (primary, secondary, and tertiary) using the dynamic chamber system. Measurements occurred during the fall of 1998 through the early spring of 1999, and each lagoon was examined for approximately one week. Analysis of flux variation was made with respect to lagoon surface water temperature (∼15 cm below the surface), lagoon water pH, total aqueous phase NHx(=NH3+NH4+) concentration, and total Kjeldahl nitrogen (TKN). Average lagoon temperatures (across all six lagoons) ranged from approximately 10.3 to 23.3°C. The pH ranged in value from 6.8 to 8.1. Aqueous NHx concentration ranged from 37 to 909 mg N l−1, and TKN varied from 87 to 950 mg N l−1. Fluxes were the largest at the primary lagoon in Kenansville, NC (March 1999) with an average value of 120.3 μg N m−2 min−1, and smallest at the tertiary lagoon in Rocky Mount, NC (November 1998) at 40.7 μg N m−2 min−1. Emission rates were found to be correlated with both surface lagoon water temperature and aqueous NHx concentration. The NH3-N flux may be modeled as ln(NH3-N flux)=1.0788+0.0406TL+0.0015([NHx]) (R2=0.74), where NH3-N flux is the ammonia flux from the lagoon surface in μg N m−2 min−1, TL is the lagoon surface water temperature in °C, and [NHx] is the total ammonia-nitrogen concentration in mg N l−1.}, number={11}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, VP and Bunton, B and Walker, JT and Malik, BP}, year={2001}, pages={1949–1958} }
 @article{aneja_agarwal_roelle_phillips_tong_watkins_yablonsky_2001, title={Measurements and analysis of criteria pollutants in New Delhi, India}, volume={27}, ISSN={["0160-4120"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034923291&partnerID=MN8TOARS}, DOI={10.1016/S0160-4120(01)00051-4}, abstractNote={Ambient concentrations of carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and total suspended particulates (TSP) were measured from January 1997 to November 1998 in the center of downtown [the Income Tax Office (ITO) located on B.S.G. Marg] New Delhi, India. The data consist of 24-h averages of SO2, NOx, and TSP as well as 8 and 24-h averages of CO. The measurements were made in an effort to characterize air pollution in the urban environment of New Delhi and assist in the development of an air quality index. The yearly average CO, NOx, SO2, and TSP concentrations for 1997 and 1998 were found to be 4810±2287 and 5772±2116 μg/m3, 83±35 and 64±22 μg/m3, 20±8 and 23±7 μg/m3, and 409±110 and 365±100 μg/m3, respectively. In general, the maximum CO, SO2, NOx, and TSP values occurred during the winter with minimum values occurring during the summer, which can be attributed to a combination of meteorological conditions and photochemical activity in the region. The ratio of CO/NOx (∼50) indicates that mobile sources are the predominant contributors for these two compounds in the urban air pollution problem in New Delhi. The ratio of SO2/NOx (∼0.6) indicates that point sources are contributing to SO2 pollution in the city. The averaged background CO concentrations in New Delhi were also calculated (∼1939 μg/m3) which exceed those for Eastern USA (∼500 μg/m3). Further, all measured concentrations exceeded the US National Ambient Air Quality Standards (NAAQS) except for SO2. TSP was identified as exceeding the standard on the most frequent basis.}, number={1}, journal={ENVIRONMENT INTERNATIONAL}, author={Aneja, VP and Agarwal, A and Roelle, PA and Phillips, SB and Tong, QS and Watkins, N and Yablonsky, R}, year={2001}, month={Jul}, pages={35–42} }
 @article{kang_aneja_zika_farmer_ray_2001, title={Nonmethane hydrocarbons in the rural southeast United States national parks}, volume={106}, ISSN={["0747-7309"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035081992&partnerID=MN8TOARS}, DOI={10.1029/2000JD900607}, abstractNote={Measurements of volatile organic compounds (VOCs) were made at three rural sites in the southeast U.S. national parks: Mammoth Cave National Park, Kentucky; Cove Mountain, Great Smoky Mountains National Park, Tennessee; and Big Meadows, Shenandoah National Park, Virginia. In 1995 the three locations were sampling sites for the Southern Oxidants Study (SOS) Nashville Intensive, and the measurements of VOCs for Shenandoah were also made under contract with the National Park Service. Starting in 1996, the National Park Service added the other two parks to the monitoring contract. Hydrocarbon measurements made during June through September for the years 1995, 1996, and 1997 were analyzed in this study. Source classification techniques based on correlation coefficient, chemical reactivity, and ratioing were developed and applied to these data. The results show that anthropogenic VOCs from automobile exhaust appeared to be dominant at Mammoth Cave National Park, and at Cove Mountain, Great Smoky Mountains National Park, but other sources were also important at Big Meadows, Shenandoah National Park. Correlation and ratio analysis based on chemical reactivity provides a basis for source-receptor relationship. The most abundant ambient VOCs varied both in concentration and order depending on park and year, but the following VOCs appeared on the top 10 list for all three sites: isoprene (6.3 to 18.4 ppbv), propane (2.1 to 12.9 ppbv), isopentane (1.3 to 5.7 ppbv), and toluene (1.0 to 7.2 ppbv). Isoprene is naturally emitted by vegetation, and the others are produced mainly by fossil fuel combustion and industrial processes. Propylene-equivalent concentrations were calculated to account for differences in reaction rates between the hydroxyl radical and individual hydrocarbons, and to thereby estimate their relative contributions to ozone formation.}, number={D3}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Kang, DW and Aneja, VP and Zika, RG and Farmer, C and Ray, JD}, year={2001}, month={Feb}, pages={3133–3155} }
 @article{moore_sullivan_roelle_aneja_2001, title={Vertical distribution of oxides of nitrogen in the semi-urban planetary boundary layer: Mixing ratios, sources and transport}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033668009&partnerID=MN8TOARS}, DOI={10.1016/S1465-9972(00)00028-3}, abstractNote={Measurements of the mixing ratios of tropospheric NO and NOY (defined as nitric oxide (NO) + nitrogen dioxide (NO2) + peroxyacetyl nitrate (PAN) + nitric acid (HNO3) + particulate nitrate (NO3−) + ⋯) were made over a semi-urban area of central North Carolina at the surface (10 m) and on a tower at heights of 250 m (820 ft) and 433 m (1420 ft) above ground level (AGL) from December 1994 to February 1995. These measurements were compared with synoptic weather data and regional and local upper air soundings in an effort to characterize NO and NOY in the planetary boundary layer in terms of their vertical distributions, diurnal profile, and related transport mechanisms. A pronounced decreasing vertical gradient in both NO and NOY mixing ratios was observed, with a distinct diurnal cycle and nocturnal minimum. Furthermore, the results suggest that NO and NOY were mixed upward from the surface during passage of synoptic meteorological features (and their associated vertical motions). Most importantly, the data reveals that mixing ratios of NO and NOY at the elevated heights did not exist in sufficient concentrations above the inversion layer in the nocturnal boundary layer to be mixed downward upon breakup of the nocturnal inversion and affect surface measurements. Instead, concentrations of NO and NOY were apparently mixed upward during the morning and midday hours by vertical boundary layer processes. Thus, the association of observed increases in surface NO and NOY mixing ratios based solely on downward mixing processes is not justified in all cases, and other sources and processes for these increases must be considered, particularly over rural areas.}, number={1}, journal={Chemosphere - Global Change Science}, author={Moore, T.C. and Sullivan, L.J. and Roelle, P.A. and Aneja, V.P.}, year={2001}, pages={7–23} }
 @article{aneja_adams_arya_2000, title={An observational based analysis of ozone trends and production for urban areas in North Carolina}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033821842&partnerID=MN8TOARS}, DOI={10.1016/S1465-9972(00)00007-6}, abstractNote={An observational based analysis of ozone production for Raleigh and Charlotte, North Carolina, was performed for the years 1981–1990. A trend analysis was carried out for the 10 yr period for Raleigh. The third quartile average for Raleigh indicated a slight upward trend of about 0.5 parts per billion by volume (ppbv) per year in ozone concentration, but this may not be statistically significant. During the period studied, Raleigh was designated as out of compliance for ozone, with a classification of moderate for non-attainment areas in 1989. There were three exceedences of the National Ambient Air Quality Standard (NAAQS) of 0.12 parts per million by volume (ppmv) each in 1980, 1983, and 1987; and 13 exceedences in 1988. Based on a regression analysis, it was identified that the variability in ozone concentration in the Raleigh area is best correlated with maximum temperature and solar radiation, and also weakly correlated with daily average wind speed and wind direction. But, the local meteorological parameters could only explain 35–53% of the total variance. A delta ozone analysis was performed to obtain an estimate of the contribution to the production of ozone made by the metropolitan areas of Raleigh and Charlotte, North Carolina. During the summer of 1989, the city of Raleigh provided an average of about 25 ppbv of additional ozone to air advecting over the city. The amount of ozone produced by the metropolitan area of Charlotte for 1984–1991 averaged about 10–15 ppbv with a slight upward trend in ozone production (1.34±0.78 ppbv per year). These values are compared to a published value of 30–40 ppbv of ozone for Atlanta, Georgia, during 1979–1987.}, number={2}, journal={Chemosphere - Global Change Science}, author={Aneja, V.P. and Adams, A.A. and Arya, S.P.}, year={2000}, pages={157–165} }
 @book{aneja_chauhan_walker_2000, title={Atmospheric ammonia emissions from swine waste storage and treatment lagoons}, number={329}, journal={Report (Water Resources Research Institute of the University of North Carolina)}, publisher={Raleigh, NC: University of North Carolina Water Resources Research Institute}, author={Aneja, V. P. and Chauhan, J. P. and Walker, J.}, year={2000} }
 @article{walker_aneja_dickey_2000, title={Atmospheric transport and wet deposition of ammonium in North Carolina}, volume={34}, ISSN={["1873-2844"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034114438&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(99)00499-9}, abstractNote={Wet deposition and transport analysis has been performed for ammonium (NH4+) in North Carolina, USA. Multiple regression analysis is employed to model the temporal trend and seasonality in monthly volume-weighted mean NH4+ concentrations in precipitation from 1983 to 1996 at six National Atmospheric Deposition Program/National Trends Network (NADP/NTN) sites. A significant (p<0.01) increasing trend beginning in 1990, which corresponds to an annual concentration increase of approximately 9.5%, is detected at the rural Sampson County site (NC35), which is located within a densely populated network of swine and poultry operations. This trend is positively correlated with increasing ammonia (NH3) emissions related to the vigorous growth of North Carolina's swine population since 1990, particularly in the state's Coastal Plain region. A source–receptor regression model, which utilizes weekly NH4+ concentrations in precipitation in conjunction with boundary layer air mass back trajectories, is developed to statistically test for the influence of a particular NH3 source region on NH4+ concentrations at surrounding NADP/NTN sites for the years 1995–1996. NH3 emissions from this source region, primarily evolving from swine and poultry operations, are found to increase NH4+ concentration in precipitation at sites up to ≈80 km away. At the Scotland County (NC36) and Wake County (NC41) sites, mean NH4+ concentrations show increases of at least 44% for weeks during which 25% or more back trajectories are influenced by this source region.}, number={20}, journal={ATMOSPHERIC ENVIRONMENT}, author={Walker, JT and Aneja, VP and Dickey, DA}, year={2000}, pages={3407–3418} }
 @article{aneja_chauhan_walker_2000, title={Characterization of atmospheric ammonia emissions from swine waste storage and treatment lagoons}, volume={105}, ISSN={["2169-8996"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033784863&partnerID=MN8TOARS}, DOI={10.1029/2000jd900066}, abstractNote={Fluxes of atmospheric ammonia-nitrogen (NH3-N, where NH3-N 5 (14/17)NH3) from an anaerobic ;2.5 ha (1 ha 5 10,000 m 2 ) commercial hog waste storage lagoon were measured during the summer of 1997 through the spring of 1998 in order to study the seasonal variability in emissions of NH3-N and its relationship to lagoon physicochemical properties. Ammonia-nitrogen fluxes were measured during each season (summer, fall, winter, and spring) using a dynamic flow through chamber system. Measured lagoon physicochemical parameters included surface lagoon temperature (T,8C, ;15 cm below surface), lagoon pH, and Total Kjeldahl Nitrogen (TKN). The pH and TKN of the surface lagoon water ranged from 7 to 8 pH units, and 500 to 750 mg N L 21 , respectively. The largest fluxes were observed during the summer (August 1997) (mean NH3-N flux 5 4017 6 987 m gNm 22 min 21 ). Fluxes decreased through the fall (December 1997) months (844 6 401 m gNm 22 min 21 ) to a minimum flux during the winter (February 1998) months (305 6 154 m gNm 22 min 21 ). Emission rates increased during spring (May 1998) (1706 6 552 m gNm 22 min 21 ), but did not reach the magnitude of fluxes observed during the summer. Lagoon emissions in eastern North Carolina were estimated to constitute ;33% of total NH3-N emissions from commercial hog operations in North Carolina based on current inventories for NH3-N emissions published by the North Carolina Division of Air Quality, North Carolina Department of Environment and Natural Resources. The ammonia flux may be predicted by an observational model log10 (NH3-N flux) 5 0.048 T, 1 2.1.}, number={D9}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Aneja, VP and Chauhan, JP and Walker, JT}, year={2000}, month={May}, pages={11535–11545} }
 @article{aneja_arya_li_murray_manuszak_2000, title={Climatology of diurnal trends and vertical distribution of ozone in the atmospheric boundary layer in urban North Carolina}, volume={50}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033627172&partnerID=MN8TOARS}, DOI={10.1080/10473289.2000.10463984}, abstractNote={ABSTRACT Vertical measurements of ozone were made on a 610-m-tall tower located about 15 km southeast of Raleigh, NC, as part of an effort by the state of North Carolina to develop a state implementation plan (SIP) for ozone control in the Raleigh Metropolitan Statistical Area. During summer 1993, 1994, and 1995, ozone was monitored at ground level, 250 m, and 433 m. Boundary layer wind, temperature, and other meteorological variable profiles were determined from balloon soundings. During summer 1996 and 1997, ozone was monitored at ground level, 76 m, 128 m, and 433 m. This paper presents the analysis and discussion of the five-year data. The evolutions of the convective boundary layer during daytime and the stable nocturnal boundary layer (NBL) were found to have marked impacts on ozone concentrations. A strong diurnal pattern, with an afternoon maximum and an early morning minimum, was dominant at ground level, but it was much weaker at elevated levels and insignificant above the NBL at night. Ozone deposition velocities at night during the measurement periods were estimated to range from 0.09 to 0.64 cm/sec. We found evidence of regional transport of ozone and/or its precursors from northwest and north of the site, which may play a role in high ozone events in the Raleigh-Durham area.}, number={1}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, VP and Arya, SP and Li, YX and Murray, GC and Manuszak, TL}, year={2000}, month={Jan}, pages={54–64} }
 @article{aneja_mathur_arya_li_murray_manuszak_2000, title={Coupling the vertical distribution of ozone in the atmospheric boundary layer}, volume={34}, ISSN={["0013-936X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034195280&partnerID=MN8TOARS}, DOI={10.1021/es990997+}, abstractNote={Vertical measurements of ozone were made on a 610 m tall tower located about 15 km southeast of Raleigh, NC, as part of an effort by the State of North Carolina to develop a State Implementation Plan (SIP) for ozone control in the Raleigh Metropolitan Statistical Area and other metropolitan areas in the state. Ozone was monitored at 10, 250, and 433 m height levels during the summer months of 1993−1995 and at 10, 76, 128, and 433 m height levels during the summer months of 1996−1997. A regional atmospheric chemistry/transport model, called Multiscale Air Quality Simulation Platform (MAQSIP), was also employed to simulate three-dimensional O3 distribution over the eastern United States for a 2-month period (June 1−July 31, 1995). Through complementary analyses of the 5-year data and the modeling results, this paper examines the vertical distribution of ozone concentrations in the atmospheric boundary layer with the emphasis on the contribution of residual ozone aloft to the ground level ozone enhancement d...}, number={11}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Aneja, VP and Mathur, R and Arya, SP and Li, YX and Murray, GC and Manuszak, TL}, year={2000}, month={Jun}, pages={2324–2329} }
 @article{peirce_aneja_2000, title={Nitric oxide emissions from engineered soil systems}, volume={126}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034163535&partnerID=MN8TOARS}, DOI={10.1061/(asce)0733-9372(2000)126:3(225)}, abstractNote={Sophisticated laboratory equipment and procedures are developed and used in controlled experi- ments to measure nitric oxide (NO) emissions ranging from 42 to 75 ng N/m 2 ? s from sludge-amended soil of concern to environmental engineers because nitric oxide emitted to the troposphere is a precursor to troublesome ozone formation and also of concern to agricultural engineers because valuable nitrogen as fertilizer is lost from the soil. Water-filled pore space is confirmed to be of critical importance to NO flux, and the upper layers of soil are determined to contribute the larger portion of the NO fluxing from the soil to the troposphere. More than 42% of the total NO flux comes from the top 1 cm of soil, with NO contributions decreasing exponentially with soil depth and very little if any tropospheric NO contributed from soil at a depth of 20 cm or greater. The results are discussed in terms of microbiological, chemical, and soil transport processes that influence NO flux from sludge-amended soil. INTRODUCTION Nitrogen oxide (NO) emissions from unamended and en- gineered soils can adversely impact local and regional air qual- ity in the lower troposphere and can directly impact public health and vegetation as subsequent ozone (O3) formation; ac- cumulation leads to pulmonary congestion, disorientation, al- tered breathing, headaches in humans, and decreased crop yields. In addition, these emissions are a direct economic con- cern because nitrogen valued as fertilizer is lost from the soil. Consequently, these emissions are studied here to gain a better understanding of their net formation, transport, and transfor- mation in the form of NO flux from the soil. With the ability to measure nitric oxide emissions under controlled conditions in the laboratory, it can be possible in the future to gain a better understanding of the mechanisms responsible for NO formation, transport, and transformation with a view to the control of NO emissions from soil into the lower troposphere. Whether or not increased NO emissions lead to ozone prob- lems in the lower troposphere is dependent on other important atmospheric variables, most notably the NO x and volatile or-}, number={3}, journal={Journal of Environmental Engineering}, author={Peirce, J.J. and Aneja, Viney}, year={2000}, pages={225–232} }
 @article{walker_nelson_aneja_2000, title={Trends in ammonium concentration in precipitation and atmospheric ammonia emissions at a coastal plain site in North Carolina, USA}, volume={34}, ISSN={["0013-936X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034284993&partnerID=MN8TOARS}, DOI={10.1021/es990921d}, abstractNote={The temporal characteristics of annual volume-weighted average ammonium (NH4+) ion concentration in precipitation and local ammonia (NH3) emissions are investigated over the period 1982−1997 at Nat...}, number={17}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Walker, J and Nelson, D and Aneja, VP}, year={2000}, month={Sep}, pages={3527–3534} }
 @article{roelle_aneja_j o'connor_robarge_kim_levine_1999, title={Measurement of nitrogen oxide emissions from an agricultural soil with a dynamic chamber system}, volume={104}, ISSN={["2169-8996"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033585537&partnerID=MN8TOARS}, DOI={10.1029/98JD01202}, abstractNote={Biogenic soil emissions of nitric oxide (NO) were measured from an intensively managed agricultural row crop (corn, Zea mays) during a 4 week period (May 15 through June 9, 1995). The site was located in Washington County, near the town of Plymouth, which is in the Lower Coastal Plain of North Carolina. Soil NO flux was determined using a dynamic flowthrough chamber technique. The measurement period was characterized by two distinguishing features: an application of nitrogen (N) fertilizer at the midpoint of the experiment and a nontypical rainfall pattern. Average NO flux prior to the application of N fertilizer was 31.5 ± 10.1 ng N m−2 s−1, and more than doubled (77.7 ± 63.7 ng N m−2 s−1) after the application of a side-dressing of N fertilizer. Average soil extractable nitrogen values did not change significantly following application of the side-dressing of N fertilizer. We attribute this failure to detect a significant difference in soil extractable nitrogen following N fertilization to the method in which the fertilizer was applied, the subsequent rainfall pattern, and the technique of soil sampling. NO flux followed the same diurnal trend as soil temperature, with maximum NO emissions coinciding with maximum soil temperature, and minimum NO emissions coinciding with minimum soil temperature. NO flux was found to increase exponentially with soil temperature, but only after fertilization. Due to subsurface irrigation practices employed by the farmer, changes in soil water content were minimal, and no relation could be drawn between soil water content and NO flux. Simultaneous measurements of NOy, NO2, and NO emissions revealed that NO and NO2 emissions represent 86 and 8.7%, respectively, of NOy emissions leaving the soil. Simultaneous NO flux measurements made by a closed box flux technique, at the same site, revealed no statistically significant differences between the two different methodologies for measuring NO flux.}, number={D1}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Roelle, P and Aneja, VP and J O'Connor and Robarge, W and Kim, DS and Levine, JS}, year={1999}, month={Jan}, pages={1609–1619} }
 @article{li_aneja_arya_rickman_brittig_roelle_kim_1999, title={Nitric oxide emission from intensively managed agricultural soil in North Carolina}, volume={104}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-17044382146&partnerID=MN8TOARS}, DOI={10.1029/1999JD900336}, abstractNote={Emissions of nitric oxide (NO) were determined from an intensively managed agricultural soil near Plymouth, in the coastal plain of North Carolina, using the dynamic chamber technique. The measurements were made over a soybean field from July 15 to August 15, 1996, as part of the project Natural Emissions of Oxidant Precursors: Validation of Techniques and Assessment (NOVA). A N-containing fertilizer was applied at the middle of the experiment in order to investigate the effect of N-fertilizers on NO emissions and to test the response of instruments. Soil water content was high during the experimental period, with water-filled pore space ranging from 49% to 67%. NO emission during this period ranged between 0.28 and 18.45 ng N m -2 s -1 , with an overall average of 5.01 ± 3.03 ng N m -2 s -1 . A normal diurnal pattern with low values at nighttime and high values during the day was observed during the prefertilization period, but a reverse diurnal pattern (high at nighttime, low in daytime) of NO emission variation was found during the postfertilization, closed-canopy period, implying that interaction among canopy development, application of fertilization, and soil parameters may affect the diurnal variation of NO emission from soils. The emissions of NO were related to soil temperature, water-filled pore space, and extractable nitrogen. Application of fertilizer at the middle of the experiment was found to disrupt the normal relations between NO emission and soil temperature and water content seen during the prefertilization period but to enhance the positive relation between NO emission and extractable N. An intercomparison of the dynamic chamber technique with the eddy-correlation technique in this experiment indicates that in spite of large differences in the magnitudes of soil NO emission and the NO flux at 5 m, the two fluxes show similar variations with time and are strongly correlated.}, number={D21}, journal={Journal of Geophysical Research Atmospheres}, author={Li, Y. and Aneja, Viney and Arya, S.P. and Rickman, J. and Brittig, J. and Roelle, P. and Kim, D.S.}, year={1999}, pages={26115–26123} }
 @article{aneja_oommen_riordan_arya_wayland_murray_1999, title={Ozone patterns for three metropolitan statistical areas in North Carolina, USA}, volume={33}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032599714&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(99)00241-1}, abstractNote={As part of an effort by the state of North Carolina to develop a State Implementation Plan (SIP) for 1-h peak ozone control, a network of ozone stations was established to monitor surface ozone concentrations across the state. Between 19 and 23 ozone stations made continuous surface measurements between 1993 and 1995 surrounding three major metropolitan statistical areas (MSAs): Raleigh/Durham (RDU), Charlotte/Mecklenburg (CLT), and Greensboro/High Point/Winston-Salem (GSO). Statistical averages of the meteorological and ozone data were performed at each Metropolitan Statistical Area (MSA) to study trends and/or relationships on high ozone days (days in which one of the MSA sites measured an hourly ozone concentration⩾90.0 ppbv). County emission maps of precursor gases, wind roses, total area averages of ozone, total downwind averages of ozone deviations, upwind averages of ozone, and a modified delta ozone analysis were all obtained and analyzed. The results of this study show a reduction in the delta ozone relative to an earlier study at RDU, but no average significant change at CLT (no comparison can be made for GSO). The statistical data analyses in this study are used to quantify the importance of local contributions and regional transport, to ozone air pollution in the MSAs.}, number={30}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, VP and Oommen, RG and Riordan, AJ and Arya, SP and Wayland, RJ and Murray, GC}, year={1999}, month={Dec}, pages={5081–5093} }
 @article{aneja_hartsell_kim_grosjean_1999, title={Peroxyacetyl nitrate in Atlanta, Georgia: Comparison and analysis of ambient data for suburban and downtown locations}, volume={49}, ISSN={["1047-3289"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033081684&partnerID=MN8TOARS}, DOI={10.1080/10473289.1999.10463786}, abstractNote={Peroxyacetyl nitrate (PAN) concentrations were measured at downtown and suburban locations in Atlanta, GA, in July and August 1992 as part of the SOS-SORP/ONA (Southern Oxidants Study-Southern Oxidants Research Program on Ozone Non-Attainment). PAN concentrations were generally higher at the downtown location than at the suburban location, but on days when the O3 concentration exceeded 80 ppbv, PAN concentrations were similar at both locations. On days when O3 did not exceed 80 ppbv, suburban PAN concentrations were much lower than downtown concentrations and resembled those reported for rural areas in the eastern United States. Regression analysis of PAN and O3 on NOx and total non-methane hydrocarbons (TNMHC) showed PAN to be most strongly dependent on morning NOx concentrations, while O3 was most dependent on morning TNMHC concentrations. NOx, PAN, and meteorological data from the suburban site were used in a one-dimensional transport model to estimate the accumulation rate of PAN to be ~1.5 x 106 molecules cm-3 sec-1. A simple kinetic model estimated peroxyacetyl radical concentrations to be ~0.5 pptv at the suburban location.}, number={2}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, VP and Hartsell, BE and Kim, DS and Grosjean, D}, year={1999}, month={Feb}, pages={177–184} }
 @article{aneja_murthy_battye_battye_benjey_1998, title={Analysis of ammonia and aerosol concentrations and deposition near the free troposphere at Mt. Mitchell, NC, USA}, volume={32}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032006928&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(97)00236-7}, abstractNote={Measurements of airborne (gaseous and aerosol), cloud water, and precipitation concentrations of ammonia (NH3) and ammonium (NH+4) compounds were made at Mt. Mitchell State Park (Mt. Gibbs, ∼2006 m MSL), North Carolina. Measurements were made from May to September during 1988 and 1989. An annular denuder system was used to determine gaseous NH3 and particulate NH+4 and nitrate (NO-3) compounds. Measurements of NH+4 in cloud and rain water samples were made during the same time period. Mean concentrations of gaseous NH3 were 0.62 μg m-3 for 1988 and 1.47 μg m-3 for 1989. Mean concentrations of fine particulate NH+4 were 1.24 μg m-3 for 1988 and 0.89 μg m-3 for 1989. The NH+4 concentrations in the cloud water were 214 and 147 μeq ℓ-1 for the 1988 and 1989 field seasons, respectively. The concentrations of NH+4 in precipitation were quite low compared to cloud ionic values in both 1988 and 1989 at 14 and 15 μeq ℓ-1, respectively. The estimated mean total deposition of NH+4 over the sampling period (5 months) of 1988 and 1989 was about 0.38 and 0.67 g N m-2 season-1, respectively. Cloud water interception contributed more nitrogen (∼70%) to the total deposition than combined wet (∼15%) and dry (∼15%) deposition.}, number={3}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, VP and Murthy, AB and Battye, W and Battye, R and Benjey, WG}, year={1998}, month={Feb}, pages={353–358} }
 @article{mcculloch_few_murray_aneja_1998, title={Analysis of ammonia, ammonium aerosols and acid gases in the atmosphere at a commercial hog farm in eastern North Carolina, USA}, volume={102}, ISSN={["0269-7491"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032417540&partnerID=MN8TOARS}, DOI={10.1016/S0269-7491(98)80042-0}, abstractNote={Measurements of atmospheric ammonia, acid gases, and ammonium aerosols were made at a commercial hog farm in Eastern North Carolina, USA, during September through December of 1997. Annular denuder systems (ADS) were used to sample gaseous (hydrogen chloride, nitrous acid, nitric acid, sulfur dioxide and ammonia) and fine aerosol (ammonium, chloride, nitrate, and sulfate) species. Ammonia and ammonium concentrations were determined by colorimetric analysis of the sample extracts. The acid gases and remaining fine particle ionic species were determined by ion chromatographic analysis of the sample extracts. Mean concentrations of the gaseous hydrogen chloride, nitrous acid, nitric acid, sulfur dioxide and ammonia were 0.743 μg/m3, 0.255 μg/m3, 0.154 μg/m3, 2.968 μg/m3, and 10.48 μg/m3, respectively. Mean concentrations of the fine particle chloride, nitrate, sulfate and ammonium were 0.321 μg/m3, 0.548 μg/m3, 3.247 μg/m3, and 1.102 μg/m3, respectively. The fine aerosol fraction was dominated by ammonium sulfate particles. A linear regression of sulfate versus ammonium by equivalent concentration showed a slope of 0.715 and r2 of 0.88. An emission factor for total ammonia nitrogen flux was estimated using a simple box model as approximately 5 to 10 kg animal−1 year−1.}, number={SUPPL. 1}, journal={ENVIRONMENTAL POLLUTION}, author={McCulloch, RB and Few, GS and Murray, GC and Aneja, VP}, year={1998}, pages={263–268} }
 @article{aneja_murray_southerland_1998, title={Atmospheric nitrogen compounds: Emissions, transport, transformation, deposition, and assessment}, number={1998 Apr. 1}, journal={Environmental Manager}, author={Aneja, V. P. and Murray, G. C. and Southerland, J.}, year={1998}, pages={22} }
 @article{aneja_murray_southerland_1998, title={Atmospheric nitrogen compounds: Emissions, transport, transformation, deposition, and assessment}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032045968&partnerID=MN8TOARS}, number={4}, journal={EM: Air and Waste Management Association's Magazine for Environmental Managers}, author={Aneja, V.P. and Murray, G.C. and Southerland, J.}, year={1998}, pages={22–25} }
 @inproceedings{aneja_roelle_o’connor_robarge_1998, title={Biogenic nitric oxide source strength in the southeast United States}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032256837&partnerID=MN8TOARS}, booktitle={Proceedings of the Air & Waste Management Association's Annual Meeting & Exhibition}, author={Aneja, Viney P. and Roelle, Paul A. and O’Connor, James R. and Robarge, Wayne P.}, year={1998} }
 @article{aneja_roelle_robarge_1998, title={Characterization of biogenic nitric oxide source strength in the southeast United States}, volume={102}, ISSN={["0269-7491"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032446054&partnerID=MN8TOARS}, DOI={10.1016/S0269-7491(98)80035-3}, abstractNote={Emissions of nitric oxide (NO) were measured during the summer of 1995 from 4 crops, located at three different sites throughout North Carolina. These sites were chosen to represent major physiographic regions of the Southeast US, in an effort to compare fluxes from different agriculturally managed soils. Emission rates were determined using a dynamic flow-through chamber system. In order to understand the NO flux from the different soil and crop types, measurements were made on corn and soybean crops in the coastal region, tobacco in the Piedmont region, and corn in the upper Piedmont region of North Carolina. Average NO fluxes were 5.5 f 2.2 ng N me2 s-‘, 20.7 + 19.2 ng N me2 s-‘, 4.1 + 1.4 ng N m-2s-1, and 8.5 2 4.9 ng N me2 s-l respectively for corn and soybean in the coastal region, tobacco in the Piedmont region, and corn in the upper Piedmont region. We were only able to detect an exponential dependence of NO flux on soil temperature at two of the locations. Tbe composite data of all the research sites revealed a general trend of increasing NO flux with soil water content or increasing extractable nitrogen in the soil, however, the day to day variations within each site did not reveal the same trends. We feel that acquisition of a soil NO flux data set in this fashion, which consists of observations collected over different points in both space and time, makes attempts to model soil NO flux in terms of different soil parameters difficult.}, number={SUPPL. 1}, journal={ENVIRONMENTAL POLLUTION}, author={Aneja, VP and Roelle, PA and Robarge, WP}, year={1998}, pages={211–218} }
 @inproceedings{roelle_o’connor_robarge_aneja_1998, title={Characterization of nitric oxide emissions from an intensively managed agricultural soil in North Carolina, U.S.A.}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032312190&partnerID=MN8TOARS}, booktitle={International Conference on Air Pollution - Proceedings}, author={Roelle, P. and O’Connor, J. and Robarge, W. and Aneja, V.P.}, year={1998}, pages={607–616} }
 @article{lawrimore_aneja_1997, title={A chemical mass balance analysis of nonmethane hydrocarbon emissions in North Carolina}, volume={35}, ISSN={["0045-6535"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0030833965&partnerID=MN8TOARS}, DOI={10.1016/S0045-6535(97)00321-4}, abstractNote={The EPA's Chemical Mass Balance Receptor Model (CMB7) was used for analysis of nonmethane hydrocarbon source-receptor relationships in the Raleigh, North Carolina Metropolitan Statistical Area (MSA). Three hour integrated ambient samples collected 15 km southeast of downtown Raleigh from 5–8 AM weekdays during August, 1993 were analyzed for speciated hydrocarbons and used as inputs in the model. Additional samples collected from 12–3 PM and 5–8 PM were also analyzed. CMB results for four source profiles, i.e. roadway, whole gas, surface coating, and isoprene were compared with the State of North Carolina's seasonally adjusted emission inventory for anthropogenic and biogenic hydrocarbon emissions. The Biogenic Emission Inventory System (BETS) was used to estimate isoprene emissions for a typical summer day in the Raleigh area. CMB results using average concentrations of the 5–8 AM samples were similar to both the anthropogenic and biogenic emission inventory. Mass balance attributed 50.5% of total nonmethane organic carbon to roadway sources, 17.0% to surface coatings, and 4.0% to isoprene sources during the 5–8 AM sampling period; compared to the emission inventory which apportioned 47.5% to mobile sources, 14.0% to surface coating sources and 6.0% to isoprene sources during the same period. Afternoon and early evening samples were used to determine the diurnal profile for isoprene and roadway sources for comparison with emission inventory profiles. CMB results showed roadway source emissions decrease from morning to the afternoon and remain relatively constant from the afternoon to early evening.}, number={11}, journal={CHEMOSPHERE}, author={Lawrimore, JH and Aneja, VP}, year={1997}, month={Dec}, pages={2751–2765} }
 @article{hagerman_aneja_lonneman_1997, title={Characterization of non-methane hydrocarbons in the rural southeast United States}, volume={31}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031543513&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(97)00223-9}, abstractNote={Measurements of non-methane hydrocarbons, as well as ozone, meteorological and trace gas data, made at four rural sites located within the southeastern United States as a part of the Southern Oxidants Study are compared. The C2–C10 hydrocarbons were obtained during the 1200–1300 local time period, once every six days from September 1992 through October 1993. The light molecular weight alkanes (ethane, propane, n-butane, iso-butane, ethene and acetylene) display a seasonal variation of a winter maximum and summer minimum. Isoprene was virtually non-existent during the winter at all sites, and averaged from 9.8 ppbC (Yorkville, Georgia) to 21.15 ppbC (Centreville, Alabama) during the summer. The C10 terpene concentration was largest during the summer period with averages ranging between 3.19 ppbC (Centreville, Alabama) and 6.38 ppbC (Oak Grove, Mississippi); winter time concentrations ranged from 1.25 to 1.9 ppbC for all sites. Propylene-equivalent concentrations were calculated to account for differences in reaction rates between the hydroxyl radical and individual hydrocarbons, and to thereby estimate their relative contribution to ozone, especially in regard to the highly reactive biogenic compounds such as isoprene. The propy-equivalent concentrations from the biogenics represent at least 65% of the total non-methane hydrocarbon sum at these four sites during the summer season. A plot of ozone versus NOγ-NO highlights the NOx limited relationship of this region.}, number={23}, journal={ATMOSPHERIC ENVIRONMENT}, author={Hagerman, LM and Aneja, VP and Lonneman, WA}, year={1997}, month={Dec}, pages={4017–4038} }
 @article{depollok_aneja_hughes_claxton_1997, title={Chemical and mutagenic analysis of volatile organic compounds in Raleigh air samples at three different elevations before, during, and after Hurricane Gordon}, volume={35}, ISSN={["0045-6535"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0343907818&partnerID=MN8TOARS}, DOI={10.1016/S0045-6535(97)00130-6}, abstractNote={Volatile organic compounds (VOCs) were collected and measured at a television tower 10 km southeast of downtown Raleigh, North Carolina at three different levels (Surface, < 1 m; Mid, 240 m; and Top, 433 m) during the summer and fall of 1994. The combined presence of ozone, arenes, and nitrogen oxides (NOx) suggested possible nitration of arenes during atmospheric mixing. Air samples, therefore, were collected using XAD-filled canisters at each level on the tower prior to, during, and after Hurricane Gordon. Collected air samples were Soxhlet extracted and analyzed with the Salmonella typhimurium microsuspension mutagenicity assay using strains YG1021 and YG1026 which are sensitive to nitrarenes. Significant mutagenicity was observed only in the Top and Mid level samples for the post-hurricane, normal weather air samples. Surface samples were not mutagenic, which suggests the long-range transport of these mutagenic nitrarenes.}, number={4}, journal={CHEMOSPHERE}, author={dePollok, FS and Aneja, VP and Hughes, TJ and Claxton, LD}, year={1997}, month={Aug}, pages={879–893} }
 @article{aneja_roelle_robarge_1997, title={Contribution of biogenic nitric oxide in urban ozone: Raleigh, NC, as a case study}, volume={31}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0030616154&partnerID=MN8TOARS}, DOI={10.1016/S1352-2310(96)00282-8}, abstractNote={Anthropogenic emissions from industrial and automotive sources within the confines of the city of Raleigh, NC have been documented by the North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management, but no direct biogenic emissions of nitric oxide (NO) from soils has yet been measured. In this study, emissions of NO were measured in Raleigh, NC, and its surrounding suburbs, in an attempt to determine the portion of the total NOx ( = NO + NO2) budget which can be attributed to biogenic sources. Residential and commercial lawns, and golf courses receiving normal fertilizer applications were chosen as the primary biogenic source of NO. Soil NO fluxes were measured using a dynamic chamber technique from 11 sites and ranged in value (hourly averages calculated from 15 min readings) from 1.24 to 23.7 ng N m−2 s−1. These hour averages were then combined with estimates of lawn acreage within the city proper, and in the surrounding suburbs, in order to develop a budget for giogenic NO emissions in Raleigh. This budget was then compared to the budget used in the Environmental Protection Agency's (EPA) Regional Oxidant Model (ROM) for photochemical modeling. Results from this comparison suggest that less than 1 % of the total NOx budget for Raleigh, NC is emitted by natural processes, and that approximately 1.2% of the nitrogen applied as fertilizer is lost via soil NO emissions. Thus, the effects of biogenic NO may be neglected in the development of a reliable plan for reducing ozone in the urban atmosphere.}, number={10}, journal={ATMOSPHERIC ENVIRONMENT}, author={Aneja, VP and Roelle, P and Robarge, WP}, year={1997}, month={May}, pages={1531–1537} }
 @inproceedings{aneja_roelle_robarge_1997, title={Contribution of biogenic nitric oxide in urban ozone: Raleigh, NC, as a case study}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031349526&partnerID=MN8TOARS}, booktitle={Proceedings of the Air & Waste Management Association's Annual Meeting & Exhibition}, author={Aneja, Viney P. and Roelle, Paul and Robarge, Wayne P.}, year={1997} }
 @article{aneja_holbrook_robarge_1997, title={Nitrogen oxide flux from an agricultural soil during winter fallow in the upper coastal plain of North Carolina, USA}, volume={47}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031194163&partnerID=MN8TOARS}, DOI={10.1080/10473289.1997.10463933}, abstractNote={Abstract Incorporation of the remaining crop residue, including the root system, of grain (soybean and corn) and fiber (cotton) crops into the soil following harvest is a common agricultural practice. The crop residue represents a substantial portion of nitrogen initially applied as fertilizer, and thus is a potential source of nitrogen for NO emissions during the winter fallow period. Fluxes of NO and NO2 were measured from fallow fields from February 7 to March 23, 1994, using a dynamic chamber technique (ambient air as the carrier gas). Average NO flux rates, as a function of previous crop residue, were 9.2 (range –4.2 to 76) ng–N m–2 s–1 for soybean, 6.1 (range –11.7 to 110) ng–N m–2 s–1 for cotton, and 4.7 (range –0.2 to 40) ng–N m–2 s–1 for corn. Maximum NO fluxes were observed in mid–morning when soil temperatures were lowest. Minimum NO flux occurred after mid–afternoon when soil temperature reached a maximum. The decrease in NO flux with increase in soil temperature (5 cm depth) reflected the exi...}, number={7}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Aneja, VP and Holbrook, BD and Robarge, WP}, year={1997}, month={Jul}, pages={800–805} }
 @inproceedings{das_aneja_1997, title={Seasonal trends in C<inf>2</inf>-C<inf>5</inf> NHMC and isoprene measured at eight rural sites in the southeastern United States}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031370789&partnerID=MN8TOARS}, booktitle={Proceedings of the Air & Waste Management Association's Annual Meeting & Exhibition}, author={Das, Mita and Aneja, Viney P.}, year={1997} }
 @article{aneja_kim_chameides_1997, title={Trends and analysis of ambient NO, NOy, CO, and ozone concentrations in Raleigh, North Carolina}, volume={34}, ISSN={["0045-6535"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031081452&partnerID=MN8TOARS}, DOI={10.1016/S0045-6535(96)00393-1}, abstractNote={Ambient concentrations of NO and NOy as well as O3 and CO were measured during August 19 to September 1, 1991 in downtown Raleigh, North Carolina as a part of the Southern Oxidants Study-Southern Oxidants Research Program on Ozone Non-Attainment (SOS-SORP/ONA). These measurements were made in an effort to provide insight into the characteristics of nitrogen oxides and their role in the formation of ozone in the urban Southeast U.S. environment. NO and NOy showed bimodal diumal variations with peaks in the morning (06:00 – 08:00 EST) and in the late evening (21:00 – 23:00 EST). These peaks at this urban site correspond to the coupled effects of rush hour traffic and meteorological conditions (i.e., variation of mixing height and dispersion conditions). The overall average NO and NOy concentrations were found to be 6.1 ± 5.4 ppbv (range: 0 to 70 ppbv) and 14.9 ± 8.1 ppbv (range: 0.3 to 110 ppbv), respectively. Average daily maxima of NO and NOy (18.3 ppbv and 27.4 ppbv) occurred during the morning. O3 showed a diumal variation with a maximum in the afternoon between 14:00 and 16:00 EST; and a mean concentration 20 ± 10 ppbv (range: 1 to 62 ppbv). Maximum O3 and CO concentrations during weekdays result from NO and CO emitted from mobile sources during the morning rush hour. Background CO concentration at Raleigh was estimated to be ∼ 470 ± 52 ppbv. A linear correlation of r2 = 0.53 between CO and NOy was observed. The ratio of CO to NOy (∼ 16) at the Raleigh site suggests that mobile sources are the major contributor to NO and NOy concentrations at the site.}, number={3}, journal={CHEMOSPHERE}, author={Aneja, VP and Kim, DS and Chameides, WL}, year={1997}, month={Feb}, pages={611–623} }
 @article{sullivan_moore_aneja_robarge_pierce_geron_gay_1996, title={Environmental variables controlling nitric oxide emissions from agricultural soils in the southeast United States}, volume={30}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0030274184&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(96)00086-6}, abstractNote={Fluxes of nitric oxide (NO) were measured during the summer of 1994 (12 July to 11 August) in the Upper Coastal Plain of North Carolina in a continuing effort to characterize NO emissions from intensively managed agricultural soils in the southeastern United States. Previous work during a similar time of year on the same soil type was characterized by severe moisture stress conditions. The summer of 1994 provided a more diverse weather pattern and as a result represented a set of measurements more typical of soil temperature and soil moisture relationships for the southeastern United States. In order to ascertain NO flux response to fertilization and crop type, measurements were made on fields with three distinct fertilizer practices and crop types, namely corn, cotton, and soybean. Average NO fluxes were 21.9 ± 18.6, 4.3 ± 3.7, and 2.1 ± 0.9 ng N m−2 s−1, respectively, for corn, cotton, and soybean. NO flux increased exponentially with soil temperature when soil water content was not limiting [> 30% Water Filled Pore Space (%WFPS)]. During conditions when soil water content was limiting, NO flux was inhibited and had no relationship with soil temperature. Above a value of 30% WFPS, increasing soil water content had no effect on NO emissions (the upper limit of %WFPS could not be estimated due to a lack of data in this regime). Below 30% WFPS, increasing soil moisture increased NO production and lower soil moistures led to decreased NO flux. Increased nitrogen fertilization rates led to higher NO fluxes. However, differences in physiological growth stages between crops confound extractable nitrogen values as decomposing root biomass in the mature corn crop added an undetermined amount of available nitrogen to the soil. Interactions between soil water content, fertilizer application, and soil temperature make it very difficult to predict day-to-day variations of NO flux from our data. There appears to be no simple relation between NO flux and the environmental variables measured in Clayton, NC during the summer of 1994.}, number={21}, journal={ATMOSPHERIC ENVIRONMENT}, author={Sullivan, LJ and Moore, TC and Aneja, VP and Robarge, WP and Pierce, TE and Geron, C and Gay, B}, year={1996}, month={Nov}, pages={3573–3582} }
 @article{aneja_kim_das_hartsell_1996, title={Measurements and analysis of reactive nitrogen species in the rural troposphere of southeast United States: Southern oxidant study site SONIA}, volume={30}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029750753&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(95)00294-4}, abstractNote={Ambient concentrations of reactive nitrogen compounds as well as total NOY were measured during June and early July 1992 at a rural site, site SONIA, in the central Piedmont region of North Carolina as a part of the Southern Oxidants Study. The measurements of reactive nitrogen species were made in an effort to provide a comprehensive understanding of nitrogen chemistry and to investigate the total nitrogen budget at the site. NOy, NO2 and NO showed diurnal variations with maxima in the morning between 0600 and 0900 EST. The maximum NOy concentration reached was ∼ 14.5 ppbv, and the maximum concentrations of NO and NO2 were 5.4 and 7.8 ppbv, respectively. The mean NOy mixing ratio was found to be 2.88 ± 1.58 ppbv (n = 743) with an average daily maximum of 3.6 ppbv. The mean mixing ratios of NO and N02 were found to be 0.15 ± 0.29 ppbv (n = 785) and 1.31 ± 0.99 ppbv (n = 769). Average daily maxima of NO and N02 were 0.4 and 2.0 ppbv, respectively. HNO3 and PAN showed diurnal variation with maxima in the afternoon and minimum in the night, and mean mixing ratios were found to be 0.67 ± 0.33 ppbv (n = 250) and 0.40 ± 0.24 ppbv (n = 578). The fractions of individual reactive nitrogen species to total NOy, were investigated and contrasted to the results from a remote marine site and rural continental sites. As in two other rural continental sites in the U.S., NOx was found to be the most abundant constituent (∼45%) of NOY; while HNO3 was the most abundant compound in NOy measured at a remote marine site. The discrepancy between the NOy, partitioning at site SONIA and the marine site is attributed to the influence of local and regional anthropogenic sources of NOx and the continental origin of the majority of air masses encountered at the site. The NOxNOy ratio and NOz ( = NOy − NOx) were used as an indicator of the chemical age of airmasses. The NOxNOy ratio showed strong positive correlations with the photochemical oxidants HNO3 (r = 0.76), PAN (r = 0.68) and 03 (r = 0.79) measured at the site. Positive correlations were found between surface wind direction and both the magnitude of NOy and the NOxNOy ratio. These correlations suggest that synoptic meteorological conditions and transport of NOx are important in the distribution of NOy and its relationship with photochemical oxidants at the site. The ozone production efficiency was illustrated by correlation of O3 and NOz and compared with other published measurements made in the Southeast U.S., and published results from a 3D Eulerian model simulation.}, number={4}, journal={Atmospheric Environment}, author={Aneja, V.P. and Kim, D.-S. and Das, M. and Hartsell, B.E.}, year={1996}, pages={649–659} }
 @article{aneja_robarge_sullivan_moore_pierce_geron_gay_1996, title={Seasonal variations of nitric oxide flux from agricultural soils in the Southeast United States}, volume={48}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0001281843&partnerID=MN8TOARS}, DOI={10.3402/tellusb.v48i5.15936}, abstractNote={Fluxes of nitric oxide (NO) were measured from the summer of 1994 to the spring of 1995 from an intensively managed agricultural soil using a dynamic flow through chamber technique in order to study the seasonal variability in the emissions of NO. The measurements were made on a Norfolk sandy loam (Fine-Loamy, Siliceous, Thermic Typic Paleudult) soil located at an agricultural research station in the Upper Coastal Plain region of North Carolina. Soil nitric oxide fluxes from 3 crops, representing 3 levels of fertilizer application (corn, 168 kg N ha −1 ; cotton, 68 kg N ha −1 ; and soybean, 0 kg N ha −1 ), were measured in each season (summer, fall, winter, and spring). Additional measured soil parameters included soil temperature, soil water content (expressed as percent water filled pore space,%WFPS), and extractable nitrogen. The greatest NO flux observed in each crop occurred during the summer (June to August) measurement period (corn, 21.9 ± 18.6 ng N m −2 s −1 ; cotton, 4.3 ± 3.7 ng N m −2 s −1 ; and soybean, 2.1 ± 0.9 ng N m −2 s −1 ). NO flux decreased in each crop through the fall months to a minimum flux in the winter. Application of fertilizer during the spring months once again produced substantial NO flux, but not as high as during the summer months. Over 80% of NO flux from the three crops measured occurred in the summer months with an estimated 5% of the nitrogen applied as fertilizer emitted as NO in a year's time. The corn crop, which had the highest amount of applied fertilizer, had the highest average yearly NO flux (7.0 ± 4.8 ng N m −2 s −1 ) followed by cotton and soybean in order (1.7 ± 1.2 ng N m −2 s −1 and 1.0 ± 0.3 ng N m −2 s- 1 , respectively). NO flux from soil tracked soil temperature very closely throughout the year, especially through the summer and spring months. However, NO flux measured under a cotton canopy decreased when soil temperature was > 25 °C and soil moisture content was < 20%WFPS. Overall, the data support the assumption that in the Southeast United States, which has naturally emitted VOC's and large acreages of fertilized soils, NO emissions from agricultural soils may result in the formation of tropospheric ozone, especially during the summer months when NO emissions are highest. DOI: 10.1034/j.1600-0889.1996.t01-4-00002.x}, number={5}, journal={Tellus, Series B: Chemical and Physical Meteorology}, author={Aneja, V.P. and Robarge, W.P. and Sullivan, L.J. and Moore, T.C. and Pierce, T.E. and Geron, C. and Gay, B.}, year={1996}, pages={626–640} }
 @article{aneja_das_1995, title={Correlation of ozone and meteorology with hydrogen peroxide in urban and rural regions of North Carolina}, volume={34}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029501219&partnerID=MN8TOARS}, DOI={10.1175/1520-0450(1995)034<1890:COOAMW>2.0.CO;2}, abstractNote={Abstract Gas-phase hydrogen peroxide (H2O2) and ozone (O3) along With other trace gases and meteorology were monitored in two distinct regimes of high- and low-NOx (urban and rural) areas in North Carolina during the summer of 1991 as part of the Southern Oxidants Study (SOS). Gas-phase hydrogen peroxide concentrations ranged from less than 0.05 to about 1.0 ppbv and from less than 0.05 to 2.0 ppbv at the urban and rural sites, respectively. A clear diurnal trend was observed at both locations, though at the urban site the H2O2 profile lagged the ozone profile by 2–3 h. At the rural site, high H2O2 concentrations were observed on certain nights. The various physical, chemical, and meteorological parameters affecting H2O2 concentrations were examined using observational-based statistical analysis. It was found that in the urban air, H2O2 concentrations increased with increasing temperature, solar radiation, and ozone concentrations but decreased with increasing NOx, carbon monoxide, and relative humidity. ...}, number={8}, journal={Journal of Applied Meteorology}, author={Aneja, V.P. and Das, M.}, year={1995}, pages={1890–1898} }
 @article{apel_calvert_zika_rodgers_aneja_meagher_lonneman_1995, title={Hydrocarbon measurements during the 1992 southern oxidants study atlanta intensive: Protocol and quality assurance}, volume={45}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029049581&partnerID=MN8TOARS}, DOI={10.1080/10473289.1995.10467383}, abstractNote={Abstract A major component of the Southern Oxidants Study (SOS) 1992 Atlanta Intensive was the measurement of atmospheric nonmethane hydrocarbons. Ambient air samples were collected and analyzed by a network of strategically located automated gas chromatography (GC) systems (field systems). In addition, an extensive canister sampling network was deployed. Combined, more than 3000 chromatograms were recorded. The SOS science team targeted for quantitative analysis 56 compounds which may be substantial contributors to ozone formation or used as air mass tracers. A quality assurance program was instituted to ensure that good measurements were being made throughout the network for each target compound. Common, high-quality standards were used throughout the network. The performance of individual field systems was evaluated during the intensive through the analysis of challenge mixtures. This methodology helped to identify and correct analytical problems as they arose.}, number={7}, journal={Journal of the Air and Waste Management Association}, author={Apel, E.C. and Calvert, J.G. and Zika, R. and Rodgers, M.O. and Aneja, V.P. and Meagher, J.F. and Lonneman, W.A.}, year={1995}, pages={521–528} }
 @article{aneja_robarge_holbrook_1995, title={MEASUREMENTS OF NITRIC-OXIDE FLUX FROM AN UPPER COASTAL-PLAIN, NORTH-CAROLINA AGRICULTURAL SOIL}, volume={29}, ISSN={["1352-2310"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028971274&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(95)00089-H}, abstractNote={Agricultural soil NO flux measurements (using a dynamic chamber technique) were made from 18 August to 1 September 1993 in the Upper Coastal Plain region of North Carolina in an effort to determine the role of natural emissions of NO on rural atmospheric photochemistry. Overall average NO flux rates increased proportionally to the level of applied fertilizer nitrogen in the agricultural soil. The soybean, cotton, and corn field measurements revealed an average NO flux of 1.79 (range −1.0–6.9) ng N m−2 s−1; 3.77 (range −0.1–38.0) ng Nm−2s−1; and 8.05 (range −0.5−52.8) ng N m−2s−1 respectively. There was a positive correlation between NO concentration near the soil surface (∼ 50 cm) and NO flux. A significant negative correlation between NO flux and ambient O3 concentration, however, supports the hypothesis that soil emissions of NO contribute to local production of O3 in rural areas.}, number={21}, journal={ATMOSPHERIC ENVIRONMENT}, author={ANEJA, VP and ROBARGE, WP and HOLBROOK, BD}, year={1995}, month={Nov}, pages={3037–3042} }
 @article{sillman_al-wali_marsik_nowacki_samson_rodgers_garland_martinez_stoneking_imhoff_et al._1995, title={Photochemistry of ozone formation in Atlanta, GA-Models and measurements}, volume={29}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028971276&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(95)00217-M}, abstractNote={Chemical measurements made during an air pollution event in Atlanta, GA have been compared with results from several photochemical simulations. Measurements included O3, primary reactive organic gases (ROG), aldehydes, PAN, total reactive nitrogen (NOy) and H2O2, with vertical profiles for primary ROG. Photochemical models using two different chemical representations and a range of assumptions about winds, vertical mixing and emissions were used to simulate the event. Results show that assumptions about vertical mixing can cause a variation in simulated surface concentrations of primary hydrocarbons of a factor of two or more. A tendency to underestimate isoprene was found in comparison with measured vertical profiles. The models tend to overestimate concentrations of HCHO, H202 and PAN in comparison with measurements. Peak O3 and concurrent NOy from helicopter measurements was used as a basis for evaluating individual model scenarios. Scenarios were developed with different O3 NOx- ROG sensitivity, but only the NOx- sensitive scenarios are consistent with measured O3, NOy and isoprene.}, number={21}, journal={Atmospheric Environment}, author={Sillman, S. and Al-Wali, K.I. and Marsik, F.J. and Nowacki, P. and Samson, P.J. and Rodgers, M.O. and Garland, L.J. and Martinez, J.E. and Stoneking, C. and Imhoff, R. and et al.}, year={1995}, pages={3055–3066} }
 @article{lawrimore_das_aneja_1995, title={Vertical sampling and analysis of nonmethane hydrocarbons for ozone control in urban North Carolina}, volume={100}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029505517&partnerID=MN8TOARS}, DOI={10.1029/95jd02367}, abstractNote={As part of an effort by the state of North Carolina to develop a State Implementation Plan for ozone control in the Raleigh Metropolitan Statistical Area (MSA), vertical measurements of C2-C10 hydrocarbons were made, in and above the surface inversion layer (SIL), as inputs to the urban airshed model (UAM). Three-hour integrated ambient air samples were collected during August 1993 from 0500–0800 eastern daylight time (EDT). Additional samples were collected from 1200–1500 and 1700–2000 EDT on selected days. Vertical sampling was achieved from a 610-m television tower located approximately 15 km southeast of the downtown area. Boundary layer wind and temperature profiles were determined by balloon soundings. For some compounds, e.g., propane, the average concentration was lower above the inversion layer (9.59 ppbC in the SIL and 2.08 ppbC above the SIL); however, other species such as 2-methylpentane had higher concentrations above the inversion layer (1.28 ppbC in and 1.40 ppbC above the SIL). In addition, the vertical distributions of hydrocarbons within the convective boundary layer were compared to the vertical distribution estimated from calculations based on surface concentration, species reactivity, and eddy diffusivity. Compounds such as isoprene and N-butane decreased as predicted by the equation, while others such as propane and benzene showed unexpected profiles. Calculations of propylene-equivalent concentrations were used to estimate the effect of reactivity on the relative importance of individual hydrocarbons. The contribution of isoprene to the local hydrocarbon budget was analyzed and surface measurements were compared with data collected in Atlanta, Georgia, during the 1992 Southern Oxidants Study. Isoprene comprised more than 70% of the total propylene-equivalent concentration in the afternoon in Raleigh but only 40% of the total in Atlanta.}, number={D11}, journal={Journal of Geophysical Research}, author={Lawrimore, J.H. and Das, M. and Aneja, V.P.}, year={1995} }
 @article{kim_aneja_robarge_1994, title={Characterization of nitrogen oxide fluxes from soil of a fallow field in the central piedmont of North Carolina}, volume={28}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028193091&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(94)90290-9}, abstractNote={NOx emissions from soils may contribute to the formation of 03 in rural areas, especially when there is substantial emissions of natural hydrocarbons from surrounding vegetation, such as in the southeastern United States. Soil NO, flux measurements were made from 6 June 1992 to 7 July 1992 in the central Piedmont region of North Carolina (Southeast Oxidants and Nitrogen Intensive Analysis site, SONIA) in an effort to determine the role of natural emissions of NO, on rural atmospheric photochemistry. The overall average NO and N02 emission rates, using a dynamic chamber technique, were found to be 1.79 ± 1.37 ng-N m−2 s−1 (range: 0.13 to 6.67 ng-N m− s−1') and -1.07 ± 0.87 ng-N m−2s−1 (range: -6.71 to 3.16ng-Nm−2s−1 respectively. Over 85% of the N02 flux measurements were negative indicating net deposition to the soil surface. No negative NO flux rates were observed. NO flux was correlated with soil temperature. There was a positive correlation between NO concentration near the soil surface (∼50 cm) and NO flux (r=0.35). The NO compensation point (1.12 ppbv) was estimated from the relationship between NO emission rate and ambient NO concentrations measured at 10 m. Both positive and negative vertical gradients of NO concentration between 10 m and soil surface were detected. The positive vertical gradients are indicative of NO transport to the site from polluted air masses. A significant negative correlation between NO flux and ambient 03 concentration (r=0.66), however, supports the hypothesis that soil emissions of NO contribute to local production of 03 in rural areas.}, number={6}, journal={Atmospheric Environment}, author={Kim, D.-S. and Aneja, V.P. and Robarge, W.P.}, year={1994}, pages={1129–1137} }
 @article{aneja_das_kim_hartsell_1994, title={Measurements and Analysis of Photochemical Oxidants and Trace Gases in the Rural Troposphere of the Southeast United States}, volume={34}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85005500546&partnerID=MN8TOARS}, DOI={10.1002/ijch.199400042}, abstractNote={Ambient concentrations of photochemical oxidants (O3, PAN, HNO3, H2O2) and various trace species including reactive nitrogen compounds as well as total NOy were measured during June and early July 1992 at a rural site, SONIA, in the central Piedmont region of North Carolina, as a part of the Southern Oxidants Study. The measurements were made in an effort to provide a comprehensive understanding of tropospheric photochemistry in the rural Southeastern United States. NOy, NO2, and NO showed diurnal variations with maxima in the morning between 0600 and 0900 EST. The maximum NOy, NO, and NO2 concentrations reached were 14.5, 5.4, and 7.8 ppbv, respectively. The mean NOy concentration was found to be 2.63 ± 1.72 ppbv (n = 819) with an average daily maximum of 3.6 ppbv. The mean concentrations of NO and NO2 for the entire period of measurement were found to be 0.18 ± 0.37 ppbv (n = 794) and 1.31 ± 0.99 ppbv/(n = 769). H2O2, HNO3, and PAN showed diurnal variation with maxima in the afternoon and minima at night. Mean concentrations were found to be 0.52 ± 0.36 ppbv (n = 312), 0.67 ± 0.33 ppbv (n = 250), and 0.41 ± 0.24 ppbv (n = 578). The NOx/NOy ratio was used as an indicator of the chemical age of airmasses and the ratio showed strong positive correlations with the photochemical oxidants HNO3 (r = 0.76), PAN (r= 0.68), and O3 (r = 0.79) measured at the site. The relationship between the accumulation rate of O3 and the deviation from the photostationary state was examined based on the measured PSS constant obtained from the values of [O3], [NO], and [NO2] measured at the site.}, number={3-4}, journal={Israel Journal of Chemistry}, author={Aneja, V.P. and Das, M. and Kim, D.?S. and Hartsell, B.E.}, year={1994}, pages={387–401} }
 @article{das_aneja_1994, title={Measurements and analysis of concentrations of gaseous hydrogen peroxide and related species in the rural Central Piedmont region of North Carolina}, volume={28}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028486303&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(94)90398-0}, abstractNote={Ambient concentrations of gas-phase total peroxides and hydrogen peroxide were measured during mid-July to mid-August 1991, and during June and early July, 1992 at a rural site. SONIA, in the rural Central Piedmont region of North Carolina as a part of the Southern Oxidants Study. Simultaneous measurements were also made of trace gases and meteorological parameters. The measurements of hydrogen peroxide were made in order to explore the behaviour of this photochemical oxidant in rural southeast U.S., and to study its correlation with ozone and meteorology. H2O2 showed a pronounced diurnal variation with peak concentrations during the afternoon (1200–1600 EST). The maximum H2O2 concentrations observed were ∼ 2.2 ppbv during the 1991 intensive, and ∼ 1.6 ppbv during 1992. The mean daytime H2O2 concentrations observed were 0.64 ± 0.56 ppbv during 1991, and 0.52 ± 0.36 ppbv during 1992, which were found to be significantly higher (at the 95% confidence level) than the nighttime averages (∼0.15 ppbv). HO2 radical concentration of ∼14 ppbv was determined from calculated H2O2 production rates. On occasion high levels of nighttime H2O2 was observed which was found to be associated with the breakdown in the stability of the nocturnal boundary layer. A 48 h back trajectory analysis performed on the air masses arriving at Site SONIA indicated that significant amounts of pollutants could be transported to this rural site from the surrounding urban areas and this could affect the H2O2 levels at this site. An observational based statistical analysis was performed. The results of correlation matrices show that H2O2 is most strongly correlated to ozone, temperature, solar radiation, and relative humidity. A multiple linear regression was carried out by regressing H2O2 on all the measured physicochemical variables. The R2 was found to be 0.81 for the 1991 data and 0.71 for 1992. A simple linear regression between H2O2 and ozone gave R2 of 0.60 and 0.39 for 1991 and 1992, respectively, when data from the entire period of measurement was included.}, number={15}, journal={Atmospheric Environment}, author={Das, M. and Aneja, V.P.}, year={1994}, pages={2473–2483} }
 @article{aneja_murthy_1994, title={Monitoring deposition of nitrogenx–Containing compounds in a high–elevation forest canopy}, volume={44}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027985703&partnerID=MN8TOARS}, DOI={10.1080/10473289.1994.10467307}, abstractNote={Measurements of airborne (gaseous and aerosol), cloud water, and precipitation concentrations of nitrogen compounds were made at Mt. Mitchell State Park (Mt. Gibbs, ~2006 m MSL), North Carolina, during May through September of 1988 and 1989, An annular denuder system was used to ascertain gaseous (nitric acid, nitrous acid, and ammonia) and particulate (nitrate and ammonium) nitrogen species, and a chemiluminescence nitrogen oxides analyzer was used to measure nitric oxide and nitrogen dioxide. Measurements of NO3 − and NH4 + ions in cloud and rain water samples were made during the same time period. Mean concentrations of gaseous nitric acid, nitrous acid, and ammonia were 1.14 μg/m3, 0.3 μg/m3, and 0.62 μg/m3 for 1988, and 1.40 μg/m3,0.3 μg/m3, and 1.47 μg/m3 for 1989, respectively. Fine particulate nitrate and ammonium ranged from 0.02 to 0.21 μg/m3 and 0.01 to 4.72 μg/m3 for 1988, and 0.1 to 0.78 μg/m3 and 0.24 to 2.32 μg/m3 for 1989, respectively. The fine aerosol fraction was dominated by ammonium s...}, number={9}, journal={Air and Waste}, author={Aneja, Viney and Murthy, A. B.}, year={1994}, pages={1109–1115} }
 @article{aneja_li_das_1994, title={Ozone case studies at high elevation in the eastern United States}, volume={29}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028030224&partnerID=MN8TOARS}, DOI={10.1016/0045-6535(94)90318-2}, abstractNote={A network of five high elevation sites (≳ 1000 m, MSL) in the eastern U.S. measured ozone, NOx, and meteorological parameters as part of the U.S. Environmental Protection Agency's Mountain Cloud Chemistry Program (MCCP) from May through October in 1986, 1987, and 1988. Analysis of the data showed that high ozone episodes (≥ 70 ppbv) at the MCCP sites occurred frequently during June and July, and were strongly correlated to synoptic scale meteorological features. A comprehensive statistical analysis was performed on the data set to investigate the relationship between ozone and meteorology. Two major ozone episodes in 1988, each lasting greater than 3 days were examined in detail. The maximum one hour average ozone concentration was ∼ 160 ppbv recorded at a southern site, Whitetop Mountain. Back trajectory analysis, at 850 mb, indicated that most MCCP sites were influenced by upwind urban and industrial source areas during high ozone episodes. Other meteorological parameters, such as temperature, and relative humidity also affect the ozone formation during the two episodes. The concentrations of NOx were higher during the ozone episodes, reflecting the photochemical production of ozone in the regional scale.}, number={8}, journal={Chemosphere}, author={Aneja, V.P. and Li, Z. and Das, M.}, year={1994}, pages={1711–1733} }
 @article{hartsell_aneja_lonneman_1994, title={Relationships between peroxyacetyl nitrate, O<inf>3</inf> and NO<inf>y</inf> at the rural Southern Oxidants Study site in central Piedmont, North Carolina, site SONIA}, volume={99}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0008822468&partnerID=MN8TOARS}, DOI={10.1029/94jd01021}, abstractNote={Ambient peroxyacetyl nitrate (PAN) concentrations were measured during June and early July 1992 at site SONIA (Southeast Oxidants and Nitrogen Intensive Analysis), a rural site in the central Piedmont region of North Carolina, as part of the Southern Oxidants Study. PAN measurements were made as part of an effort to provide a comprehensive chemical climatology and to investigate the total nitrogen budget at this site. Gas chromatograph-electron capture detector (GC-ECD) was used to measure PAN every 15 min with a detection limit of 50 parts per trillion by volume. During the measurement period, maximum ambient levels of PAN reached 1.2 parts per billion by volume and averaged 0.41±0.24 ppbv (n = 1972) with an average daily maximum of 0.60 ppbv. The average daytime (0900–2100 EST) concentration was 0.52±0.24 ppbv (n = 986) while the average nighttime (2100–0900) concentration was 0.29±0.07 ppbv (n =986). The O3/PAN ratio was found to be 138±98 (n = 984) and the PAN/NOy ratio was 0.12±0.11 (n = 454). Hourly average PAN and O3 concentrations showed a strong correlation with R = 0.57 (n = 984). Moreover, the composite hourly averages of PAN and O3 for the entire measurement period showed an even stronger correlation of R = 0.95. The strong correlation between O3 and PAN suggest that mesoscale photochemical production plays a major role in PAN chemistry at site SONIA. An analysis of 10 m meteorological data suggests some correlation between regional meteorological conditions and between both the daily PAN maxima and the magnitude of the O3/PAN ratio.}, number={D10}, journal={Journal of Geophysical Research}, author={Hartsell, B.E. and Aneja, V.P. and Lonneman, W.A.}, year={1994} }
 @article{skelly_aneja_robarge_joslin_mclaughlin_1994, title={Response}, volume={44}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027944252&partnerID=MN8TOARS}, number={3}, journal={Journal of the Air and Waste Management Association}, author={Skelly, J.M. and Aneja, V.P. and Robarge, W.P. and Joslin, J.D. and McLaughlin, S.B.}, year={1994}, pages={285–286} }
 @article{aneja_claiborn_li_murthy_1994, title={Trends, seasonal variations, and analysis of high-elevation surface nitric acid, ozone, and hydrogen peroxide}, volume={28}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028450142&partnerID=MN8TOARS}, DOI={10.1016/1352-2310(94)90140-6}, abstractNote={Atmospheric photochemical oxidants nitric acid, ozone, and hydrogen peroxide were monitored in ambient air at Mt Mitchell State Park, North Carolina. Ozone measurements made from May to September during 1986–1990 are reported for two high-elevation sites (Site I on Mt Gibbs, approximately 2006 m; and Site 2 on Commissary Ridge, approximately 1760 m). These measurements are also compared to those from a nearby, low-elevation site (Fairview, approximately 830 m). Average ozone concentrations increased from lower to higher elevations. Meteorological analysis shows an association between periods of high ozone concentrations and synoptic-scale patterns. No discernible diurnal cycle in the ozone concentrations was observed at Site 2; however, a reversed diurnal cycle (nighttime maximum) was evident at Site 1. Gas-phase hydrogen peroxide and nitric acid concentration were measured at Site I during 1988 and 1989, and typically range from 0 to 4 ppbv, and 0–2 ppbv, respectively. Seasonal analysis shows that the ozone maximum occurs during spring coincident with the spring maximum at Whiteface Mountain, NY, Mauna Loa in Hawaii, and at Alpine stations in Europe, suggesting that ozone production is a hemispheric rather than local phenomenon and that the underlying phenomenon affects perhaps the entire Northern Hemisphere. The diurnal cycle of gaseous hydrogen peroxide was similar to the high-elevation ozone signal, while gaseous nitric acid concentration peaked during the day. This apparent discrepancy in the diurnal cycle between the three atmospheric photochemical oxidants at high elevation may be due to a difference in the behavior of the altitudinal gradients of those oxidants resulting from a combination of photochemistry, meteorology and dynamic processes.}, number={10}, journal={Atmospheric Environment}, author={Aneja, V.P. and Claiborn, C.S. and Li, Z. and Murthy, A.}, year={1994}, pages={1781–1790} }
 @article{aneja_1994, title={Workshop on the intercomparison of methodologies for soil NO(x) emissions: Summary of discussion and research recommendations}, volume={44}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0028001136&partnerID=MN8TOARS}, DOI={10.1080/10473289.1994.10467297}, abstractNote={A workshop on the intercomparison of methodologies for soil NOx emissions was held on March 14-15, 1994 at North Carolina State University (NCSU) in Raleigh, North Carolina, in preparation for a field experiment tentatively scheduled for May-June, 1995 involving measurement of rural site NOx emissions. The workshop was sponsored jointly by the U.S. Environmental Protection Agency (EPA) and NCSU. Representatives from several agencies will participate in the experiment, including the EPA, NASA, NOAA, DOE, NCAR, Atmospheric Science from the University of Maryland, and Atmospheric Sciences and Soil Sciences from NCSU. Approximately 50 workshop attendees, which included national experts on all aspects of flux measurement technologies, met for a day and a half to discuss techniques for measuring soil NOx (= NO + NO2) emissions and to suggest how to best incorporate these techniques into a field experiment to compare NOx measuring methodologies. The need for more knowledge in the area of soil NOx emissions is re...}, number={8}, journal={Journal of the Air and Waste Management Association}, author={Aneja, V.P.}, year={1994}, pages={977–982} }
 @article{aneja_1993, title={Chemical dynamics of clouds at mt. mitchell, north carolina}, volume={43}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027172574&partnerID=MN8TOARS}, DOI={10.1080/1073161X.1993.10467185}, abstractNote={The role of clouds as the primary pathway for deposition of air pollutants into ecosystems has recently acquired much attention. Moreover, the acidity of clouds is highly variable over short periods of time. Cloud water collections were made at Mt. Mitchell State Park, North Carolina, using a real-time cloud and rain acidity/ conductivity (CRAC) analyzer during May to September 1987, 1988 and 1989 in an effort to explore extremes of chemical exposure. On the average, the mountain peak was exposed to cloud episodes about 70 percent of experimental days. The lowest pH of cloud water in nearly real-time (∼10 min.) samples was 2.4, while that in hourly integrated samples was 2.6. The cloud pH during short cloud events (mean pH 3.1), whjch results from the orographic lifting mechanism, was lower than that during long cloud events (mean pH 3.5), which are associated with mesoscale or synoptic atmospheric disturbances. On the average, the pH values in nonprecipitating cloud events were about 0.4 pH unit lower th...}, number={8}, journal={Air and Waste}, author={Aneja, V.P.}, year={1993}, pages={1074–1083} }
 @inproceedings{ringler_aneja_1993, title={Ground-based intercomparison of path-integrated DOAS measurements and conventional point measurements of ambient trace-gas concentrations}, volume={1715}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027229821&partnerID=MN8TOARS}, booktitle={Proceedings of SPIE - The International Society for Optical Engineering}, author={Ringler, Eric S. and Aneja, Viney P.}, year={1993}, pages={303–311} }
 @article{aneja_1993, title={Organic compounds in cloud water and their deposition at a remote continental site}, volume={43}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027338614&partnerID=MN8TOARS}, DOI={10.1080/1073161X.1993.10467201}, abstractNote={Some organic compounds (alkylbenzene, chlorinated hydrocarbons and poiycyclic aromatic hydrocarbons) in clouds have been determined from samples collected above the canopy of a coniferous forest. The cloud samples were collected during 1987 and 1988 at Mt. Mitchell State Park, North Carolina, a remote high elevation (∼2006 m MSL) continental site. Concentrations of the organic chemicals in clouds were in the range of 0.2 to ∼200 ng mL-1; and their estimated deposition rates via clouds were found to range from 1.58 * 104 to 4.67 * 106 ng m-2 yr-1. Great variations in concentrations were found which can best be explained, based on 72 hour back trajectory analysis, by different source locales and moving air masses. The concentration of these chemicals exceeded their water solubility as predicted by Henry's Law, suggesting that clouds are an excellent scavenger of organic chemicals in the ambient environment.}, number={9}, journal={Air and Waste}, author={Aneja, V.P.}, year={1993}, pages={1239–1244} }
 @article{claiborn_aneja_1993, title={Transport and Fate of Reactive Trace Gases in Red Spruce Needles. 1. Uptake of Gaseous Hydrogen Peroxide as Measured in Controlled Chamber Flux Experiments}, volume={27}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027338649&partnerID=MN8TOARS}, DOI={10.1021/es00048a042}, abstractNote={Foliar uptake by plants represents an important sink for many air pollutants. In this, the first of two companion papers, a continuous-flow, well-mixed exposure chamber was used to study the fluxes of gaseous hydrogen peroxide to red spruce saplings. Wall losses were found to be substantial and highly variable, requiring frequent wall loss measurements throughout the course of the experiments. No significant difference was observed between daytime and nighttime losses of hydrogen peroxide to the needle branches (.)}, number={12}, journal={Environmental Science and Technology}, author={Claiborn, C.S. and Aneja, V.P.}, year={1993}, pages={2585–2592} }
 @article{claiborn_carbonell_aneja_1993, title={Transport and Fate of Reactive Trace Gases in Red Spruce Needles. 2. Interpretations of Flux Experiments Using Gas Transport Theory}, volume={27}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027338650&partnerID=MN8TOARS}, DOI={10.1021/es00048a043}, abstractNote={A mathematical description of the multicomponent transport of gaseous species into needles of conifer trees is presented. Detailed physiology of the stomatal zone is taken into account, and diffusion through the atmospheric boundary layer, wax-filled antechamber, stomata, and substomatal cavity are described starting from the fundamental equations for multicomponent gas diffusion. The model was used to analyze the results from two sets of exposure experiments in which red spruce saplings were exposed to gas-phase H202 or to a combination of H202, S02, and 03. Model calculations indicate that the waxfilled antechamber may provide a porous zone in which water can condense, thus protecting the sensitive inner tissues below the stomata from exposure to water-soluble, toxic, trace gases (such as SO2 and H202). The model was found to be sensitive to the accuracy of measurements of leaf temperature, dewpoint temperature of the chamber inlet and exit air, and gas flow rate and may provide some insight into the role of atmospheric pollutants in forest decline. ~}, number={12}, journal={Environmental Science and Technology}, author={Claiborn, C.S. and Carbonell, R.G. and Aneja, V.P.}, year={1993}, pages={2593–2605} }
 @article{aneja_robarge_claiborn_murthy_sookim_zheng_cowling_1992, title={CHEMICAL CLIMATOLOGY OF HIGH ELEVATION SPRUCE FIR FORESTS IN THE SOUTHERN APPALACHIAN MOUNTAINS}, volume={75}, ISSN={["0269-7491"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026613849&partnerID=MN8TOARS}, DOI={10.1016/0269-7491(92)90061-E}, abstractNote={The physical and chemical climatology of high elevation (> 1500 m) spruce-fir forests in the southern Appalachian mountains was studied by establishing a weather and atmospheric chemical observatory at Mt Mitchell State Park in North Carolina (35 degrees 44' 05" N, 82 degrees 17' 15"W). Data collected during the summer and autumn (May-October) of 1986, 1987, and 1988 are reported. All measurements were made on or near a 16.5 m walk-up tower extending 10 m above the forest canopy on Mt Gibbes (2006 m msl), which is located approximately 2 km SW of Mt Mitchell. The tower was equipped with standard meteorological instrumentation, a passive cloud water collector, and gas pollutant sensors for O3, SO2, NOx. The tower and nearby forest canopy were immersed in clouds 25 to 40% of the time. Non-precipitating clouds were very acidic (pH 2.5-4.5). Precipitating clouds were less acidic (pH 3.5-5.5). The dominant wind directions were WNW and ESE. Clouds from the most common wind direction (WNW) were more acidic (mean pH 3.5) than those from the next most common wind direction (ESE, mean pH 5.5). Cloud water acidity was related to the concentration of SO4(2-), and NO3- ions. Mean concentration of H+, NH4+, SO4(2-), and NO3- ions in the cloud water varied from 330-340, 150-200, 190-200 and 120-140 micromol litre(-1) respectively. The average and range of O3 were 50 (25-100) ppbv (109) in 1986, 51 (26-102) ppbv in 1987, and 66 (30-140) during the 1988 field seasons, respectively. The daily maximum, 1-h average, and 24-h average concentrations were all greatest during June through mid-August, suggesting a correlation with the seasonal temperature and solar intensity. Throughfall collectors near the tower were used to obtain a useful estimate of deposition to the forest canopy. Between 50-60% of the total deposition of SO4(2-) was due to cloud impact.}, number={1}, journal={ENVIRONMENTAL POLLUTION}, author={ANEJA, VP and ROBARGE, WP and CLAIBORN, CS and MURTHY, A and SOOKIM, D and ZHENG, L and COWLING, EB}, year={1992}, pages={89–96} }
 @article{aneja_li_1992, title={Characterization of ozone at high elevation in the eastern United States: trends, seasonal variations, and exposure}, volume={97}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0027069657&partnerID=MN8TOARS}, DOI={10.1029/92JD00503}, abstractNote={Ozone measurements at five high-elevation (≳ 1000 m msl) Mountain Cloud Chemistry Program (MCCP) sites in the eastern United States for the period from May to October 1986–1988 have been analyzed. In order to characterize and compare the exposure to ozone at these sites, several ozone exposure indices are used. The sum of all hourly mean ozone concentrations equal to or greater than 0.07 ppm (SUM07) for 1988 indicates a north-south gradient in ozone exposure: Southeastern sites (Mount Mitchell, North Carolina, 105 parts per million-hours (ppm-h), Whitetop Mountain, Virginia, 85.7 ppm-h, Shenandoah Park, Virginia, 51.6 ppm-h); Northeastern sites (Whiteface Mountain, New York, 49.2 ppm-h, Mount Moosilauke, New Hampshire, 34.2 ppm-h). This shows that forest areas in the southeastern high-elevation sites experienced higher ozone exposure than their northeastern counterparts during the hot and dry 1988 measurement season. Ozone episodes (concentrations greater than 70 ppbv lasting 8 hours or more) were more frequent during the summer months at all sites. This suggests a correlation with the seasonal photochemical cycle and perhaps with local biogenic hydrocarbon emissions. Seasonal analysis suggests that ozone maximum occurs during spring coincident with spring maximum at Mauna Loa, Hawaii and at Alpine stations in Europe, suggestive of an underlying hemispheric phenomena. A reversed diurnal cycle (nighttime maximum) pattern was also observed from May to October at all the five high-elevation sites. Back trajectory analysis, during high-ozone episodes, indicates that most MCCP sites were influenced by urban and industrial sources from the midwestern region of the United States, suggesting large-scale transport patterns.}, number={D9}, journal={Journal of Geophysical Research}, author={Aneja, V.P. and Li, Zheng}, year={1992}, pages={9873–9888} }
 @article{kim_aneja_1992, title={Chemical composition of clouds at Mt. Mitchell, North Carolina, USA}, volume={44}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84982719938&partnerID=MN8TOARS}, DOI={10.1034/j.1600-0889.1992.00004.x}, number={1}, journal={Tellus B}, author={KIM, D.?S. and ANEJA, V.P.}, year={1992}, pages={41–53} }
 @article{kim_aneja_1992, title={Microphysical Effects on Cloud Water Acidity: A Case Study in a Nonprecipitating Cloud Event Observed at mt. Mitchell, North Carolina}, volume={42}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026731692&partnerID=MN8TOARS}, DOI={10.1080/10473289.1992.10467083}, abstractNote={There is increasing recognition that deposition of cloud water may significantly contribute to the decline of forest. In this paper, chemical and microphysical data obtained at Mt. Mitchell, North Carolina during one orographic, non-precipitating cloud event are examined to investigate the relationship between temporal variation of cloud acidity and cloud microphysics. The cloud acidity was substantially higher than in precipitating cloud events. Sulfate, nitrate, ammounium and hydrogen ions were the major constituents. The results suggest that water vapor condensation and evaporation of cloud droplets are the dominant processes in determining the total concentration of cloud water. 18 refs., 6 figs.}, number={10}, journal={Journal of the Air and Waste Management Association}, author={Kim, D.-S. and Aneja, V.P.}, year={1992}, pages={1345–1349} }
 @article{aneja_yoder_arya_1992, title={Ozone in the urban southeastern United States}, volume={75}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026613844&partnerID=MN8TOARS}, DOI={10.1016/0269-7491(92)90054-E}, abstractNote={Ozone measurements (daily maximum values) from the Aerometric Information Retrieval System database are analyzed for selected sites, during 1980 to 1988, in southeastern USA. Frequency distributions, for most sites during most years, show a typical bell-shaped curve with the higher frequency around the yearly daily maximum ozone mean of about 100 to about 110 microg m(-3) (50-55 ppbv). Abnormal years in ozone concentration may skew the distribution as the mean shifts. A correlation of daily maximum ozone concentrations above 140 microg m(-3) (70 ppbv) between sites shows a division between the sites in the northern protion of the region and those in the southern portion of the region. Variations in ozone levels are well correlated over distances of several hundred kilometers, suggesting that high values are associated with synoptic scale episodes. An ozone exposure analysis also shows higher ozone exposures (250-300 ppm days) in the northerly sites as compared to the southerly sites (150-170 ppm days).}, number={1}, journal={Environmental Pollution}, author={Aneja, V.P. and Yoder, G.T. and Arya, S.P.}, year={1992}, pages={39–44} }
 @article{li_aneja_1992, title={Regional analysis of cloud chemistry at high elevations in the eastern United States}, volume={26}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026908649&partnerID=MN8TOARS}, DOI={10.1016/0960-1686(92)90085-Y}, abstractNote={Results from the collection and chemical analysis of cloudwater samples collected from May to October 1986–1988 from the five high-elevation (⪆950 m MSL) Mountain Cloud Chemistry Program (MCCP) sites (Whiteface Mountain, NY; Mt Moosilauke, NH; Shenandoah Park, VA; Whitetop Mountain, VA; Mt Mitchell, NC) in the eastern United States are summarized. The resulting database documents the regional chemical climatology of high-elevation forest ecosystems in the eastern U.S. Clouds occured at these sites on 32–77% of the days during the sample collection period. More than 90% of cloud samples were acidic (prmpH<5.0). The lowest cloudwater pH (2.29 integrated 1-h collection period) was recorded at Mt Mitchell, NC. At all sites sulfate and nitrate were the dominant anions and hydrogen and ammonium were the dominant cations in cloudwater samples. Mount Mitchell received the most acidic clouds and highest chemical exposures, while the Whiteface summit site received the least acidic and lowest chemical exposures compared to other MCCP high-elevation sites. Cloud pH and major chemical components exhibited a seasonal trend with the maxima during the summer months, and correlated well with temperature and ozone concentrations. The mean equivalent ratios of SO42− to NO3− were found to be 1.9–3.9 at these sites. It is noted that SO42− correlated highly with hydrogen ion, suggesting that contribution to cloud acidity by sulfate and/or its precursors may be significant.}, number={11}, journal={Atmospheric Environment Part A, General Topics}, author={Li, Z. and Aneja, V.P.}, year={1992}, pages={2001–2017} }
 @article{claiborn_aneja_1991, title={Measurements of atmospheric hydrogen peroxide in the gas phase and in cloud water at Mt. Mitchell, North Carolina}, volume={96}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026305278&partnerID=MN8TOARS}, DOI={10.1029/91jd00931}, abstractNote={Measents of atmospheric hydrogen peroxide in the gas phawa'e made during four latemire observon periods at the Mt. Mitchell State Park, Noah Carolina, during the growing sea, on (May through September) of 1988. Cloud water hydrogen peroxide was measured during the entire field semon of 1988 and during the late rummet and fall of 1987 (Augtat and October). Cloud water concentrations were found to be similar to those reported from another high-elevation location in the southeastvaUnited Statee. Cloud wattamplee coilacted during these periods showed a wide range of levels (- 0 - 219/aM/L) and average values of 38/zM/L, and 44 /zM/L for the entire sampling seasons of 1988 and 1987. respectively. Significant seasonal variation was noted both in 1987 and 1988, with cloud water levels of hydrogen peroxide much higher in the summer than in the fall. Gas-phase hydrogen peroxide levels ranged from the detection limit (0.1 ppbv) to above 4 ppbv. Gas-phase hydrogen peroxide demonstrated a nighttime maximum in the summer but not in the fall. The measurements taken in the fall were significantly lower than those taken during the summer, possibly due at least in part to seasonal variation. Atmospheric hydrogen peroxide levels were found to be incrv, asing during stagnating high- pressure systems and were found to correspond to the back trajectory of the air mass with the highest conecatratiom corresponding to conLineatal air masses. The hydrogen peroxide concentration was also found to be affby radical formation from ozone and by lcpmcassee such as wet and dry deposition. LVIRODUON}, number={D10}, journal={Journal of Geophysical Research}, author={Claiborn, C.S. and Aneja, V.P.}, year={1991} }
 @article{aneja_businger_li_claiborn_murthy_1991, title={Ozone climatology at high elevations in the southern Appalachians}, volume={96}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0026094997&partnerID=MN8TOARS}, DOI={10.1029/90JD02022}, abstractNote={Ozone measurements are reported for two high-elevation sites located in the Mt. Mitchell State Park in North Carolina (site 1 on Mt. Gibbs, ---2006 m, and site 2 on Commissary Ridge, ---1760 m). These measurements are also compared to those from a nearby, low-elevation site (Fairview, ---850 m). The measurements were made from May through September during the years 1986 and 1988 and from May through October during 1987, at sites 1 and 2. Measurements were also made from May through September 1989 at site 1 only. During the monitoring season at site 1 the mean ozone concentrations were 50, 51, 66, and 52 ppbv for 1986, 1987, 1988, and 1989 field seasons, respectively, while at site 2 the mean ozone concentrations were 49, 49 and 52 ppbv for 1986, 1987, and 1988. (It has been shown that exposure to ozone concentrations of ->50 ppbv is sufficient to cause damage to certain species of vegetation.) The daily maximum, 1-hour average, and 24-hour average concentrations were found to be greatest during summer months (late May through early July), with lower concentrations during fall (August and September), suggesting a correlation with the seasonal photochemical cycle. It is suggested that excess hydrocarbons released during budbreak may contribute to the seasonal signal in the ozone data. During the 1988 monitoring season there were three periods of very high ozone levels (>80 ppbv) which lasted over 100 hours. During these long episodes there were 48 hours during which ozone concentrations exceeded the current National Ambient Air Quality Standard (NAAQS) of 0.12 ppmv. High hourly averaged SO2 (---25 ppbv) and NOx ('" 11 ppbv) levels were also found during these episodes. Meteorological analyses show an association between periods of high ozone concentrations and synoptic-scale patterns. Such high gaseous pollutant concentrations were not observed during the previous two field seasons. Also, no exceedances of the NAAQS were observed during the field season of 1989. No discernible diurnal cycle in the ozone concentrations was observed at site 2; however, a reversed diurnal cycle (nighttime maximum) was evident at site 1. Also, average ozone concentrations increased from lower elevations to higher elevations. Evidence suggests that the relationship between the mountaintop and the height of the mixing layer, coupled with horizontal transport of ozone in the lower troposphere, may be important in explaining the nocturnal maximum at site 1 and the observed altitudinal gradient in ozone.}, number={D1}, journal={Journal of Geophysical Research}, author={Aneja, V.P. and Businger, S. and Li, Zheng and Claiborn, C.S. and Murthy, A.}, year={1991}, pages={1007–1021} }
 @inproceedings{kim_aneja_1990, title={Chemical composition of clouds at Mt. Mitchell, North Carolina}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025682264&partnerID=MN8TOARS}, booktitle={CHEMECA '90, Australasian Chemical Engineering Conference}, author={Kim, Deug-Soo and Aneja, Viney P.}, year={1990}, pages={175–182} }
 @article{aneja_claiborn_bradow_paur_baumgardner_1990, title={Dynamic chemical characterization of montane clouds}, volume={24}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025243060&partnerID=MN8TOARS}, DOI={10.1016/0960-1686(90)90011-B}, abstractNote={Cloud water collections have been made on Mt. Mitchell using a nearly real-time cloud and rain acidity/conductivity (CRAC) analyzer. Results are reported for integrating times of approximately 5 min during several cloud events in the summer and fall of 1987. Both pH and ionic strength during cloud events were found to be much more variable than previously indicated by cloud collection. Maximum values of H+ and SO42− ion concentrations in 5-min samples were as much as 2.5 times greater than those measured in 1-h integrated collections. These results are not influenced by instrumental variability to any measurable extent. Results from repeated quality control samples were highly reproducible, and agreement between integrated collection data and the average values of 5-min sequential samples was also very good.}, number={3}, journal={Atmospheric Environment Part A, General Topics}, author={Aneja, V.P. and Claiborn, C.S. and Bradow, R.L. and Paur, R.J. and Baumgardner, R.E.}, year={1990}, pages={563–572} }
 @article{aneja_claiborn_li_murthy_1990, title={Exceedances of the National Ambient Air Quality Standard for Ozone Occurring at a “Pristine” Area Site}, volume={40}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025214171&partnerID=MN8TOARS}, DOI={10.1080/10473289.1990.10466680}, abstractNote={The authors present ozone measurements for high elevation pristine area sites in the Mt. Mitchell, North Carolina State Park located in the southeastern United States. These data have been collected as part of an on-going project, one of the goals of which is to assess rural ozone exposure. They may also provide insight into those processes which affect rural ozone levels, and perhaps might guide policy makers in developing strategies for rural ozone control.}, number={2}, journal={Journal of the Air and Waste Management Association}, author={Aneja, V.P. and Claiborn, C.S. and Li, Z. and Murthy, A.}, year={1990}, pages={217–220} }
 @book{aneja_aneja_jacob_1990, title={Hydrodynamics in a polycondensation semi-batch ractor}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85041141682&partnerID=MN8TOARS}, author={Aneja, A.P. and Aneja, V.P. and Jacob, K.I.}, year={1990} }
 @inproceedings{aneja_aneja_jacob_1990, title={Hydrodynamics in a polycondensation semi-batch reactor}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025591219&partnerID=MN8TOARS}, booktitle={CHEMECA '90, Australasian Chemical Engineering Conference}, author={Aneja, Arun P. and Aneja, Viney P. and Jacob, Karl I.}, year={1990}, pages={1204–1211} }
 @article{aneja_1990, title={NATURAL SULFUR EMISSIONS INTO THE ATMOSPHERE}, volume={40}, ISSN={["2162-2906"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025412897&partnerID=MN8TOARS}, DOI={10.1080/10473289.1990.10466701}, abstractNote={Natural atmospheric sulfur emission rates are reviewed for important components of the sulfur cycle. A summary of emission estimates is provided for vegetation, coastal and wetland ecosystems, inland soils, and oceanic environments. A brief discussion of sea salt sulfate, aeolian sources, volcanic activity, and biomass burning is also included. The emissions from plants and inland soils, may play a significant role in global sulfur cycling and very little work has been reported covering this subject. Large uncertainties continue to exist in the identity and the emission rates of the sulfur compounds and thus it is not reasonable to extrapolate these data in an attempt to balance the global sulfur cycle. Moreover interactions of enhanced anthropogenic activity with various components of the sulfur cycle need to be considered.}, number={4}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={ANEJA, VP}, year={1990}, month={Apr}, pages={469–476} }
 @article{aneja_overton_1990, title={The emission rate of dimethyl sulfide at the atmospheric-oceanic interface}, volume={98}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0013591121&partnerID=MN8TOARS}, DOI={10.1080/00986449008911570}, abstractNote={Dimethyl sulfide appears to be present everywhere in the surface ocean, is readily transferred into the marine atmosphere, and may account for about 30% of the natural component of the overall sulfur budget in the atmosphere. To investigate the apparent discrepancies between measured DMS fluxes, and theoretical predictions, we have examined the transport of DMS across the marine-atmosphere interface. An analysis of vertical flux was performed with a two-film model for the transport of DMS across the marine-atmosphere interface with chemical reactions. The photosensitized oxidation of DMS, its reaction with hydrogen peroxide in the aqueous film, and reactions with nitrate and hydroxyl radicals in the gas film have negligible effect on the DMS flux to the marine atmosphere. However, the flux of DMS into the atmosphere is most sensitive to the liquid-film thickness but not to changes in temperature and gas-film thickness. Model calculations showed that if the liquid-film thickness increases from 35 μm (turbu...}, number={1}, journal={Chemical Engineering Communications}, author={Aneja, V.P. and Overton, J.H.}, year={1990}, pages={199–209} }
 @inproceedings{aneja_overton_1989, title={Emission rate of dimethyl sulfide at the atmospheric - oceanic interface and its role in global climate change}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0024868793&partnerID=MN8TOARS}, number={pt2}, booktitle={Coastal Zone: Proceedings of the Symposium on Coastal and Ocean Management}, author={Aneja, Viney P. and Overton, John H.}, year={1989}, pages={1311–1332} }
 @book{aneja_claiborn_li_murthy_1989, title={Measurements at high elevation of oxidants in the eastern United States and their role in forest decline}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0024917949&partnerID=MN8TOARS}, journal={Man and his ecosystem. Proc. 8th World Clean Air Congress. The Hague, 1989. Vol. 2}, author={Aneja, V.P. and Claiborn, C.S. and Li, Zheng and Murthy, A.}, year={1989}, pages={189–193} }
 @inproceedings{aneja_businger_li_claiborn_murthy_1989, title={Ozone climate at Mt. Mitchell, North Carolina, and its association with synoptic episodes}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0024775423&partnerID=MN8TOARS}, booktitle={Proceedings - A&WMA Annual Meeting}, author={Aneja, Viney P. and Businger, Steven and Li, Zheng and Claiborn, Candis and Murthy, Anuradha}, year={1989} }
 @article{aneja_overton_durham_1987, title={Sulfate aerosol formation rate in an oil fired power plant plume}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0023243632&partnerID=MN8TOARS}, DOI={10.1080/09593338709384476}, abstractNote={Abstract In February 1977, a study was conducted to obtain the atmospheric rate of sulfate formation in an oil‐fired power plant plume. The power plant studied is located 70 km northwest of Tampa, Florida, and during the study period it was burning fuel oil that contained about 2 percent sulfur and significant concentrations (‐ 250 ppm) of vanadium. Aerial sampling was performed to obtain the sulfur dioxide and sulfate concentrations in the plume. The wind flow field was also measured. Analysis of the data indicates no conversion (0.00014 hr‐1 ±0.00053) of SO2 to sulfate in that region of the plume where data was collected (plume age > 20 minutes). However plume fall‐out of particulate sulfate before sampling began is not ruled out.}, number={1-12}, journal={Environmental Technology Letters}, author={Aneja, V.P. and Overton, J.H. and Durham, J.L.}, year={1987}, pages={167–180} }
 @article{aneja_1986, title={Characterization of emissions of biogenic atmospheric hydrogen sulfide}, volume={38 B}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84989132986&partnerID=MN8TOARS}, DOI={10.1111/j.1600-0889.1986.tb00091.x}, number={2}, journal={Tellus B}, author={ANEJA, V.P.}, year={1986}, pages={81–86} }
 @article{aneja_1986, title={Characterization of emissions of biogenic atmospheric hydrogen sulfide.}, volume={38 B}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0022848901&partnerID=MN8TOARS}, DOI={10.3402/tellusb.v38i2.15081}, abstractNote={The emission rate measurements of H 2 S into the atmosphere from coastal marine sediments were made by the use of an emission flux reactor (chamber) technique under deaerated (gaseous N 2 ) and aerated (ambient air) conditions. The emission rates of H 2 S varied over a wide range (>0.05 to < 100 gS m -2 yr -1 ) . The emission of H 2 S was inversely related to the stage of tidal hydrology, with incoming and outgoing tidal hydrostatic pressure affecting the gaseous release at the locale. The diurnal studies showed an enhancement in the emission rates at night; however the emission rate of H 2 S is unaffected by increasing light intensity (between 100 and 90,000 lux) at constant temperature. The emission rates of H 2 S are greater in the deaerated chamber than in the aerated chamber. The measured marine fluxes of ~0.1 gS m -2 yr -1 seem to agree well with those derived from global marine sulfur budgets. DOI: 10.1111/j.1600-0889.1986.tb00091.x}, number={2}, journal={Tellus, Series B}, author={Aneja, V.P.}, year={1986}, pages={81–86} }
 @article{aneja_rogers_stahel_1986, title={Dry deposition of ammonia at environmental concentrations on selected plant species}, volume={36}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0022834118&partnerID=MN8TOARS}, DOI={10.1080/00022470.1986.10466183}, abstractNote={The deposition velocity of NH/sub 3/ on six plant species at environmental concentrations has been studied in a dynamic plant gas exchange reactor. The total resistance to the transport of NH/sub 3/ was studied. The aerodynamic resistance was determined directly by NH/sub 3/ gas absorption in aqueous solutions at environmental concentrations in a two-phase gradientless reactor modeling the transfer processes through the stomata in a leaf. The concentration of NH/sub 3/ in the gas phase ranged from 50 to 1000 ppb and the temperature varied from 25 to 30/sup 0/C. The results for the deposition velocity for NH/sub 3/, during the day, varied from 0.3 to 1.3 cm/s. The deposition velocities at night were about one order of magnitude smaller. These results are compared with estimates from the Froessling equation which consistently yields higher values of the same order of magnitude. To determine accurate atmospheric transport models or global budget models, a variable deposition velocity should be used to account for the diurnal and seasonal variations in the surface resistance.}, number={12}, journal={Journal of the Air Pollution Control Association}, author={Aneja, V.P. and Rogers, H.H. and Stahel, E.P.}, year={1986}, pages={1338–1341} }
 @article{ibusuki_aneja_1984, title={Mass transfer of NH<inf>3</inf> into water at environmental concentrations}, volume={39}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0021295277&partnerID=MN8TOARS}, DOI={10.1016/0009-2509(84)85076-9}, abstractNote={The mass transfer of NH3, into water at environmental concentrations has been studied in a two-phase flow reactor. The concentration of NH3 in water ranged from 10−6 to 10−4 mole l.−1 and the temperature was chjanged from 12 to 30°C. At the conditions of this experiment, the overall mass transfer coefficient (K) is more dependent on the hydrodynamics of the gas phase than of the liquid phase. No significant concentration or temperature effects on the value of K have been observed. The mass transport of NH3 is interpreted in terms of the individual gas phase and liquid phase mass transfer coefficients.}, number={7-8}, journal={Chemical Engineering Science}, author={Ibusuki, T. and Aneja, V.P.}, year={1984}, pages={1143–1155} }
 @article{aneja_adams_pratt_1984, title={Summary of an APCA International Specialty Conference}, volume={34}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0021640473&partnerID=MN8TOARS}, DOI={10.1080/00022470.1984.10465813}, abstractNote={Because man now influences the chemistry of the biosphere in so many important ways, it is essential that we understand the complex interrelationships among the chemicals from natural as well as anthropogenic sources and the factors that influence their life cycles. One important grouping of chemical species which influence the atmosphere are the naturally occurring compounds of sulfur, hydrocarbons, halocarbons and nitrogen. While significant efforts have been directed toward the control of similar anthropogenic air pollutants, very limited support has been provided for developing an understanding of the role of natural emissions in air pollution control. Based on the realization that there may be specific cases where control of anthropogenic sources may have only minimal impact on air quality problems and since resources for basic research on the impacts of natural emissions are limited, the Air Pollution Control Association through the Technical Committee on Interactions with the Total Environment sponsored an International Specialty Conference on the Environmental Impact of Natural Emissions. The following brief report is only intended to convey the flavor of the conference. The transactions of the conference will be available from APCA headquarters and are highly recommended.}, number={8}, journal={Journal of the Air Pollution Control Association}, author={Aneja, V.P. and Adams, D.F. and Pratt, C.D.}, year={1984}, pages={799–803} }
 @article{aneja_aneja_1983, title={EFFECT OF WATER AND AIR CONTAMINATION ON POLY(ETHYLENE TEREPHTHALATE) FORMATION.}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0020602248&partnerID=MN8TOARS}, number={2}, journal={Polymer Engineering Reviews}, author={Aneja, Arun Pal and Aneja, Viney Pal}, year={1983}, pages={123–133} }
 @article{aneja_aneja_adams_1982, title={Biogenic Sulfur Compounds and the Global Sulfur Cycle}, volume={32}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0020000491&partnerID=MN8TOARS}, DOI={10.1080/00022470.1982.10465466}, abstractNote={Sulfur compounds of biogenic origin are thought to constitute a significant fraction of the atmospheric sulfur burden. Experimental determination of the biogenic fluxes of these compounds into the atmosphere is required to assess accurately the relative contributions of the anthropogenic and the biogenic fraction of the natural sources to such important phenomena as the atmospheric sulfate burden and acid precipitation. A review of the literature describing field measurements of biogenic sulfur compounds at different kinds of emission locales to include both generation processes (sulfate reduction and plant decomposition) of volatile sulfur production show a great variation in the emission rate measurements associated primarily with wide variations in the surface and climatic environments of the various study sites. Although the maximum emission rate measurements balance the global sulfur cycle, the average measurement values do not, indicating the need for more experimental investigations in order to cha...}, number={8}, journal={Journal of the Air Pollution Control Association}, author={Aneja, V.P. and Aneja, A.P. and Adams, D.F.}, year={1982}, pages={803–807} }
 @article{aneja_overton_aneja_1981, title={Emission survey of biogenic sulfur flux from terrestrial surfaces}, volume={31}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0019539303&partnerID=MN8TOARS}, DOI={10.1080/00022470.1981.10465218}, abstractNote={The most critical gap in knowledge important for delineating the global atmospheric cycle of sulfur is uncertainty about the magnitude, distribution, source, and form of biogenic emissions to the atmosphere. All global sulfur budget estimates which have appeared recently in the literature require a substantial biogenic sulfur emission to balance the budget; however, the estimated magnitude of the global natural source strengths vary widely—from ∼35 to ∼280 TgS/yr. Direct measurements of sulfur emission rates were made by sampling various terrestial surfaces (water surfaces, soil, and selected vegetation) during 1978. An emission flux reactor (chamber) technique was used to determine the emission rates of sulfur compounds into the atmosphere. The sulfur gases were identified and their concentrations in the flux reactor measured with a gas chromatograph equipped with a flame photometric detector specific for S. H2S (average flux ∼0.5 gS/m2/yr), (CH3)2S (average flux ∼0.4 gS/m2/yr), COS (average flux ∼0.03 g...}, number={3}, journal={Journal of the Air Pollution Control Association}, author={Aneja, V.P. and Overton, J.H. and Aneja, A.P.}, year={1981}, pages={256–258} }
 @article{influence of gaseous nitric acid on sulfate production and acidity in rain_1981, volume={15}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0019389865&partnerID=MN8TOARS}, DOI={10.1016/0004-6981(81)90106-2}, abstractNote={Abstract A physico-chemical subcloud rain model is used to simulate the effect of gaseous HNO 3 and NO x on pH and SO 2− 4 production in a 10mmh −1 , 1000-m fall distance rain event The ambient gases considered in the chemistry were SO 2 , NO, NO 2 , HNO 3 , O 3 , and CO 2 . Raindrops initially at a pH of 5.5 absorbed these gases, and as they fell through a polluted zone, produced SO 2− 4 and NO − 3 by the oxidation of dissolved SO 2 by O 3 and the dissociation of HNO 3 , which reduced the pH. For the chemical mechanism and the below-cloud washout rain events considered, it was observed that: absorption of gaseous HNO 3 controlled the acidification in the initial stages of a rain event, and inhibited the production of SO 2− 4 ; NO and NO 2 played no direct role in the acidification or formation of NO − 3 or SO 2− 4 ; pre-acidified raindrops (pH of 4) were further acidified only by absorbing HNO 3 .}, number={6}, journal={Atmospheric Environment (1967)}, year={1981}, pages={1059–1068} }
 @article{effect of moisture on the release of biogenic sulfur compounds._1980, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0019340522&partnerID=MN8TOARS}, journal={Proceedings, Annual Meeting - Air Pollution Control Association}, year={1980} }
 @article{aneja_overton_cupitt_durham_wilson_1980, title={Measurements of emission rates of carbon disulfide from biogenic sources and its possible importance to the stratospheric aerosol layer}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018919018&partnerID=MN8TOARS}, DOI={10.1080/00986448008935943}, abstractNote={MEASUREMENTS OF EMISSION RATES OF CARBON DISULFIDE FROM BIOGENIC SOURCES AND ITS POSSIBLE IMPORTANCE TO THE STRATOSPHERIC AEROSOL LAYER V.P. ANEJA a , J.H. OVERTON JR. a , L.T. CUPITT a , J.L. DURHAM b & W.E. WILSON b a Environmental Sciences Group, Northrop Services, Incorporated , Research Triangle Park, North Carolina, 27709 b U.S. Environmental Protection Agency , Research Triangle Park, North Carolina, 27711 Published online: 24 Apr 2007.}, number={6}, journal={Chemical Engineering Communications}, author={Aneja, V.P. and Overton, J.H. and Cupitt, L.T. and Durham, J.L. and Wilson, W.E.}, year={1980}, pages={721–727} }
 @article{rogers_aneja_1980, title={UPTAKE OF ATMOSPHERIC AMMONIA BY SELECTED PLANT-SPECIES}, volume={20}, ISSN={["0098-8472"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0001178961&partnerID=MN8TOARS}, DOI={10.1016/0098-8472(80)90022-2}, abstractNote={Rates of NH3 uptake were measured for 10 crop species by direct kinetic techniques. A continuous stirred tank reactor (CSTR) system designed for plant gas exchange studies was used in the NH3 exposures. Ammonia was monitored with an analyzer that permitted real time measurement of atmospheric NH3 down to 5 ppb. This permitted measurement of dynamic sorption of NH3 at concentrations much closer to ambient levels than previously reported. Uptake rates increased with increasing light, temperature, and NH3 concentration. An inverse correlation was observed between total diffusion resistance of leaves and NH3 sorption. Rates did not vary significantly with repeated exposure or with changes in growth media N.}, number={3}, journal={ENVIRONMENTAL AND EXPERIMENTAL BOTANY}, author={ROGERS, HH and ANEJA, VP}, year={1980}, pages={251–257} }
 @article{aneja_overton_cupitt_durham_wilson_1979, title={Carbon disulphide and carbonyl sulphide from biogenic sources and their contributions to the global sulphur cycle [7]}, volume={282}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018677862&partnerID=MN8TOARS}, DOI={10.1038/282493a0}, number={5738}, journal={Nature}, author={Aneja, V.P. and Overton, J.H. and Cupitt, L.T. and Durham, J.L. and Wilson, W.E.}, year={1979}, pages={493–496} }
 @article{direct measurements of emission rates of some atmospheric biogenic sulfur compounds._1979, volume={31}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018667469&partnerID=MN8TOARS}, DOI={10.3402/tellusa.v31i2.10423}, abstractNote={Direct measurements of H 2 S + COS and (CH 3 ) 2 S emission rates were made in two salt marshes on the coast of North Carolina during the summer of 1977. An emission flux reactor (chamber) technique was used to determine the emission rates of sulfur compounds into the atmosphere. The sulfur gases were identified and their concentrations in the flux reactor measured with a gas chromatograph equipped with a flame photometric detector specific for S. Flux measurements were made over salt marsh grass ( Spartina alterniflora ) and mud flats. The predominant gaseous sulfur species being emitted over the Spartina zone is (CH 3 ) 2 S (average flux is ?0.66 g S/m 2 /yr), and the predominant species over the mud flat zone is H 2 S + COS (average flux is ?0.2 g S/m 2 /yr). In general, the emission rates of (CH 3 ) 2 S and H 2 S + COS increase with increasing ambient temperature (in accordance with previously reported work over mud flats). Similar experiments were also performed in which the chamber was operated under deaerated (N 2 ) conditions. For deaerated conditions, the emission rates of both H 2 S + COS and (CH 3 ) 2 S were increased. DOI: 10.1111/j.2153-3490.1979.tb00895.x}, number={2}, journal={Tellus}, year={1979}, pages={174–178} }
 @article{aneja_aneja_1979, title={Process options for polyester}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-18744426171&partnerID=MN8TOARS}, author={Aneja, A.P. and Aneja, V.P.}, year={1979} }
 @article{production of sulfate in rain and raindrops in polluted atmospheres_1979, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018332064&partnerID=MN8TOARS}, DOI={10.1016/0004-6981(79)90292-0}, abstractNote={A physico-chemical model for the accumulation of sulfur species in raindrops is developed in which account is taken of the mass transfer of SO2, O3, NH3 and CO2 into ideal raindrops containing the catalyst Fe(III). The sulfur accumulation was calculated for the droplets as a function off all distance. The model predicts the formation of sulfate due to the oxidation of dissolved SO2 by O3 and catalytic ions in the presence of NH3 and CO2. The initial pH of a drop was taken as 5.56. The final value depended on drop size, fall distance, and ambient concentrations, but in all cases was between 4.2 and 6.6. Sulfate values also depended on the same conditions and ranged from 2 to 2000 μmol 1−1 for individual drops. For a precipitation rate of 10 mm h−1 and a fall distance of 2000 m, the raindrop pH varied from 4.5 to 6.5 and the average sulfate concentration from 3 to 87 μmol 1−1 depending on ambient pollutant concentrations. These results conform to the experimentally measured values of the rain pH (3–9) and sulfate concentration (20–150 μmol 1−1), and corresponding air SO2 concentration (1–10 ppb) as reported in the literature.}, number={3}, journal={Atmospheric Environment (1967)}, year={1979}, pages={355–367} }
 @article{hill_aneja_felder_1978, title={A technique for measurement of biogenic sulfur emission fluxes}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0017873840&partnerID=MN8TOARS}, DOI={10.1080/10934527809374804}, abstractNote={Abstract Atmospheric sulfur compounds of biogenic origin are thought to constitute a significant fraction of the atmospheric sulfur burden. Determination of fluxes of these compounds into the atmosphere is desirable in order to permit accurate assessment of the relative roles of anthropogenic and biogenic sources in contributing to such phenomena as the atmospheric sulfate burden and acidity in precipitation. In the present paper an emission flux measurement technique for biogenic sulfur compounds is described, and initial resuits of the use of the technique in a Long Island salt marsh are presented. These first known measurements of biogenic fluxes are compared to estimates of biogenic fluxes derived from global sulfur budgets and from calculations based on a simple mass transfer model. Comparison is also made with anthropogenic emission rates expressed as fluxes. Further steps in the development of the technique are suggested.}, number={3}, journal={Journal of Environmental Science and Health. Part A: Environmental Science and Engineering}, author={Hill, F.B. and Aneja, V.P. and Felder, R.M.}, year={1978}, pages={199–225} }
 @article{aneja_stahel_rogers_witherspoon_heck_aneja_stahel_1978, title={Calibration and Performance of a Thermal Converter in Continuous Atmospheric Monitoring of Ammonia}, volume={50}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018217741&partnerID=MN8TOARS}, DOI={10.1021/ac50034a036}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCalibration and performance of a thermal converter in the continuous atmospheric monitoring of ammoniaV. P. Aneja, E. P. Stahel, H. H. Rogers, A. M. Witherspoon, and W. W. HeckCite this: Anal. Chem. 1978, 50, 12, 1705–1708Publication Date (Print):October 1, 1978Publication History Published online1 May 2002Published inissue 1 October 1978https://doi.org/10.1021/ac50034a036RIGHTS & PERMISSIONSArticle Views44Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (449 KB) Get e-Alerts Get e-Alerts}, number={12}, journal={Analytical Chemistry}, author={Aneja, V.P. and Stahel, E.P. and Rogers, H.H. and Witherspoon, A.M. and Heck, W.W. and Aneja, V.P. and Stahel, E.P.}, year={1978}, pages={1705–1708} }
 @inproceedings{direct measurements of emission rates of some atmospheric biogenic sulfur compounds._1978, volume={18}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0018106297&partnerID=MN8TOARS}, number={2}, booktitle={ACS Division of Environmental Chemistry, Preprints}, year={1978} }
 @article{aneja_aneja_1978, title={PET process options}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0017824836&partnerID=MN8TOARS}, author={Aneja, A.P. and Aneja, V.P.}, year={1978} }
 @article{so<inf>2</inf> flux to a falling raindrop in a polluted atmosphere._1977, volume={75}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0017627203&partnerID=MN8TOARS}, number={188}, journal={AIChE Symposium Series}, year={1977}, pages={151–157} }
 @article{pal aneja_pal aneja_1977, title={STRATEGY OF PROCESS TRANSLATION.}, volume={20}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0017559942&partnerID=MN8TOARS}, number={6}, journal={Res Manage}, author={Pal Aneja, Arun and Pal Aneja, Viney}, year={1977}, pages={37–40} }
 @article{nitrogen and carbon }