Species are expected to shift their distributions to higher latitudes, greater elevations, and deeper depths in response to climate change, reflecting an underlying hypothesis that species will move to cooler locations. However, there is significant variability in observed species range shifts and differences in exposure to climate change may explain some of the variability amongst species. But this requires identifying regions that have experienced detectable changes in those aspects of the climate system that species are sensitive to.
To better understand species exposure to climate change, we estimate the time of emergence of climate change for 19 biologically relevant climate variables using observations and initial condition large ensembles from five different climate models. The time of emergence (ToE) is calculated using Signal/Noise (S/N) thresholds. The S/N threshold applied in this study is >=2, but this threshold can be easily modified to represent species that are more or less sensitive to climate change. Preliminary findings from the initial condition large ensembles indicates the strongest emergence for the temperature metrics within the tropical oceanic regions in the absence of upwelling. The earliest emergence over the oceans is found within the western warm pool of the Pacific. Notable places that haven’t emerged for the temperature metrics include both the North Atlantic and Pacific. The ToE of a climate change signal for the temperature metrics over land is spatially complex, which may partially explain the complex observed range shifts for terrestrial species. For instance, multiple initial condition large ensembles indicate a signal has emerge in the most recent decades only for the western and northeastern parts United States.
}, publisher={Copernicus GmbH}, author={Bowden, Jared and Suarez-Gutierrez, Laura and Terando, Adam J. and Rubenstein, Madeleine and Carter, Shawn and Weiskopf, Sarah and Nguyen, Hai Thanh}, year={2022}, month={Mar} } @article{pedruzzi_andreao_baek_hudke_glotfelty_freitas_martins_bowden_pinto_alonso_et al._2022, title={Update of land use/land cover and soil texture for Brazil: Impact on WRF modeling results over Sao Paulo}, volume={268}, ISSN={["1873-2844"]}, DOI={10.1016/j.atmosenv.2021.118760}, abstractNote={Land Use/Land Cover (LULC) and soil texture play a key role in meteorological models because they determine the vegetation and soil proprieties that interfere in the exchange of energy, moisture, and momentum between the land surface and the atmosphere. Additionally, LULC and soil texture are relevant input datasets in meteorological models affecting their results and future applicability as in weather researches and air quality modeling. Brazil has a complex and heterogeneous LU, and it has faced significant LULC changes in the past years. Therefore, this paper aims to update the LULC, using the national product MapBiomas, and soil texture data, by SoilGrids, to replace the default input data in the Weather Research and Forecast (WRF) model for São Paulo, Brazil. Aiming to evaluate the impact of those input data on WRF simulations, five cases were simulated using WRF v4.1.3 with 1 km of grid resolution, and combinations of "Default" and "Updated" input data. Sixty-days simulations from March 15th to May 15th of 2015, covering the transition of wet to dry season, were performed and evaluated with observational data over São Paulo State. The results showed significant differences in the classifications of LULC and soil texture in the entire domain between the default and updated data. The updated data is more realistic and coherent with local characteristics, being more representative, as an example over Santos city area being correctly classified as urban and built-in updated LULC and not water, as in the default. The comparison between the modeled results with observations data has shown a similar behavior for temperature and humidity for the five cases at the monitoring stations grid cells because the LULC changes were between classes with similar land parameters, such as albedo, roughness length, and soils moisture, although the Default classes are not accurate. However, the latent and sensible heat fluxes were ways more sensitive to the LULC/soil texture changes in the WRF model. Additionally, reasonable differences were observed over the entire modeling domain for these two variables. The updated land surface data provoked low temperatures at 9h and 17h UTC, less humidity at 9h UTC, and more humidity at 17h UTC, especially in the north part of the modeling domain, the area which has faced more LULC and soil changes. The PBL height was also affected by the updated data, probably caused by the impact at heat flux over the domain, causing a variation from 30% to 70% over the modeled grid cell, which may have a higher impact on air quality modeling. Thus, it is recommended to update the land surface data for Brazil to avoid misclassification of LULC and soil texture, even if the comparison at monitoring stations has shown similar behavior between the default and updated land surface data. Additionally, updates in the land parameter inside the model are required to represent each LULC/soil class better.}, journal={ATMOSPHERIC ENVIRONMENT}, author={Pedruzzi, Rizzieri and Andreao, Willian Lemker and Baek, Bok Haeng and Hudke, Anderson Paulo and Glotfelty, Timothy William and Freitas, Edmilson Dias and Martins, Jorge Alberto and Bowden, Jared H. and Pinto, Janaina Antonino and Alonso, Marcelo Felix and et al.}, year={2022}, month={Jan} } @article{bowden_terando_misra_wootten_bhardwaj_boyles_gould_collazo_spero_2021, title={High‐resolution dynamically downscaled rainfall and temperature projections for ecological life zones within Puerto Rico and for the U.S. Virgin Islands}, url={https://doi.org/10.1002/joc.6810}, DOI={10.1002/joc.6810}, abstractNote={Abstract}, journal={International Journal of Climatology}, author={Bowden, Jared H. and Terando, Adam J. and Misra, Vasu and Wootten, Adrienne and Bhardwaj, Amit and Boyles, Ryan and Gould, William and Collazo, Jaime A. and Spero, Tanya L.}, year={2021}, month={Feb} } @article{glotfelty_ramirez-mejia_bowden_ghilardi_west_2021, title={Limitations of WRF land surface models for simulating land use and land cover change in Sub-Saharan Africa and development of an improved model (CLM-AF v. 1.0)}, volume={14}, ISSN={["1991-9603"]}, url={https://doi.org/10.5194/gmd-14-3215-2021}, DOI={10.5194/gmd-14-3215-2021}, abstractNote={Abstract. Land use and land cover change (LULCC) impacts local and regional climates through various biogeophysical processes. Accurate representation of land surface parameters in land surface models (LSMs) is essential to accurately predict these LULCC-induced climate signals. In this work, we test the applicability of the default Noah, Noah-MP, and Community Land Model (CLM) LSMs in the Weather Research and Forecasting (WRF) model over Sub-Saharan Africa. We find that the default WRF LSMs do not accurately represent surface albedo, leaf area index, and surface roughness in this region due to various flawed assumptions, including the treatment of the MODIS woody savanna land use and land cover (LULC) category as closed shrubland. Consequently, we developed a WRF CLM version with more accurate African land surface parameters (CLM-AF), designed such that it can be used to evaluate the influence of LULCC. We evaluate meteorological performance for the default LSMs and CLM-AF against observational datasets, gridded products, and satellite estimates. Further, we conduct LULCC experiments with each LSM to determine if differences in land surface parameters impact the LULCC-induced climate responses. Despite clear deficiencies in surface parameters, all LSMs reasonably capture the spatial pattern and magnitude of near-surface temperature and precipitation. However, in the LULCC experiments, inaccuracies in the default LSMs result in illogical localized temperature and precipitation changes. Differences in thermal changes between Noah-MP and CLM-AF indicate that the temperature impacts from LULCC are dependent on the sensitivity of evapotranspiration to LULCC in Sub-Saharan Africa. Errors in land surface parameters indicate that the default WRF LSMs considered are not suitable for LULCC experiments in tropical or Southern Hemisphere regions and that proficient meteorological model performance can mask these issues. We find CLM-AF to be suitable for use in Sub-Saharan Africa LULCC studies, but more work is needed by the WRF community to improve its applicability to other tropical and Southern Hemisphere climates. }, number={6}, journal={GEOSCIENTIFIC MODEL DEVELOPMENT}, author={Glotfelty, Timothy and Ramirez-Mejia, Diana and Bowden, Jared and Ghilardi, Adrian and West, J. Jason}, year={2021}, month={Jun}, pages={3215–3249} } @article{jalowska_spero_bowden_2021, title={Projecting changes in extreme rainfall from three tropical cyclones using the design-rainfall approach}, volume={4}, ISSN={["2397-3722"]}, url={https://doi.org/10.1038/s41612-021-00176-9}, DOI={10.1038/s41612-021-00176-9}, abstractNote={Abstract}, number={1}, journal={NPJ CLIMATE AND ATMOSPHERIC SCIENCE}, author={Jalowska, Anna M. and Spero, Tanya L. and Bowden, Jared H.}, year={2021}, month={Mar} } @misc{nolte_spero_bowden_sarofim_martinich_mallard_2021, title={Regional temperature-ozone relationships across the US under multiple climate and emissions scenarios}, volume={71}, ISSN={["2162-2906"]}, DOI={10.1080/10962247.2021.1970048}, abstractNote={ABSTRACT The potential effects of 21st century climate change on ozone (O3) concentrations in the United States are investigated using global climate simulations to drive higher-resolution regional meteorological and chemical transport models. Community Earth System Model (CESM) and Coupled Model version 3 (CM3) simulations of the Representative Concentration Pathway 8.5 scenario are dynamically downscaled using the Weather Research and Forecasting model, and the resulting meteorological fields are used to drive the Community Multiscale Air Quality model. Air quality is modeled for five 11-year periods using both a 2011 air pollutant emission inventory and a future projection accounting for full implementation of promulgated regulatory controls. Across the U.S., CESM projects daily maximum temperatures during summer to increase 1–4°C by 2050 and 2–7°C by 2095, while CM3 projects warming of 2–7°C by 2050 and 4–11°C by 2095. The meteorological changes have geographically varying impacts on O3 concentrations. Using the 2011 emissions dataset, O3 increases 1–5 ppb in the central Great Plains and Midwest by 2050 and more than 10 ppb by 2095, but it remains unchanged or even decreases in the Gulf Coast, Maine, and parts of the Southwest. Using the projected emissions, modeled increases are attenuated while decreases are amplified, indicating that planned air pollution control measures ameliorate the ozone climate penalty. The relationships between changes in maximum temperature and changes in O3 concentrations are examined spatially and quantified to explore the potential for developing an efficient approach for estimating air quality impacts of other future climate scenarios. Implications: The effects of climate change on ozone air quality in the United States are investigated using two global climate model simulations of a high warming scenario for five decadal periods in the 21st century. Warming summer temperatures simulated under both models lead to higher ozone concentrations in some regions, with the magnitude of the change increasing with temperature over the century. The magnitude and spatial extent of the increases are attenuated under a future emissions projection that accounts for regulatory controls. Regional linear regression relationships are developed as a first step toward development of a reduced form model for efficient estimation of the health impacts attributable to changes in air quality resulting from a climate change scenario.}, number={10}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Nolte, Christopher G. and Spero, Tanya L. and Bowden, Jared H. and Sarofim, Marcus C. and Martinich, Jeremy and Mallard, Megan S.}, year={2021}, month={Oct}, pages={1251–1264} } @article{aircraft landing and takeoff emission impacts on surface o3 and pm2.5 through aerosol direct feedback effects estimated by the coupled wrf-cmaq model_2020, url={http://dx.doi.org/10.1016/j.atmosenv.2020.117859}, DOI={10.1016/j.atmosenv.2020.117859}, abstractNote={The aerosol direct feedback effects (ADFEs) are neglected in traditional air quality modeling studies (where meteorology is used as input and not affected by the chemistry and aerosol microphysics) for estimating the impacts of aircraft emissions on air quality. In this study, aircraft landing and take-off (LTO) attributable change of O3 and PM2.5 concentrations through ADFEs for the year 2005 within the contiguous United States (CONUS) are quantified by a coupled meteorology-chemistry modeling system: Weather Research and Forecasting – Community Multi-scale Air Quality (WRF-CMAQ) model. We first quantified the effects of ADFEs of all aerosols within the CONUS (not the effects of aircraft LTO emissions) on surface meteorology and air quality and found that ADFEs changed on average the downward short-wave radiation (SWR), 2-m temperature (T2), planetary boundary layer (PBL) height, O3 and PM2.5 by −7.38 W/m2, −0.47 K, −20.72 m, −0.41 ppb and +0.28 μg/m3 in 2005. We also found a seasonal influence where ADFE-influenced change (decrease) of SWR, T2, PBL, O3 and change (increase) of PM2.5 were higher in summer than in winter. We found that the aircraft LTO emissions' contribution to domain average surface concentration of O3 and PM2.5 were +0.0065 ppb and +0.0022 μg/m3 respectively when ADFEs are accounted for. The ADFEs decrease aircraft LTO attributable surface O3 and PM2.5 change by 21% and 23% respectively comparing with that without ADFE in 2005. We also found that in both without-and-with ADFE cases, the aircraft LTO emissions increases domain average of O3 from April to October and decreases from November to March showing a strong seasonal pattern. Our modeling study revealed that use of a coupled model with ADFE shows localized changes in air quality by aircraft LTO emissions across the domain which were masked when looking at domain averages for both O3 and PM2.5, and which may be important for accurately quantifying health risk due to air pollution exposures in densely populated areas.}, journal={Atmospheric Environment}, year={2020}, month={Aug} } @article{glotfelty_ramírez-mejía_bowden_ghilardi_west_2020, title={Limitations of WRF land surface models for simulating land use and land cover change in Sub-Saharan Africa and development of an improved model (CLM-AF v. 1.0)}, volume={8}, url={https://doi.org/10.5194/gmd-2020-193}, DOI={10.5194/gmd-2020-193}, abstractNote={Abstract. Land use and land cover change (LULCC) impacts local and regional climates through various biogeophysical processes. Accurate representation of land surface parameters in land surface models (LSMs) is essential to accurately predict these LULCC-induced climate signals. In this work, we test the applicability of the default Noah, Noah-MP, and CLM LSMs in the Weather Research and Forecasting Model (WRF) over Sub-Saharan Africa. We find that the default WRF LSMs do not accurately represent surface albedo, leaf area index, and surface roughness in this region due to various flawed assumptions, including the treatment of the MODIS woody savanna LULC category as closed shrubland. Consequently, we developed a WRF CLM version with more accurate African land surface parameters (CLM-AF), designed such that it can be used to evaluate the influence of LULCC. We evaluate meteorological performance for the default LSMs and CLM-AF against observational datasets, gridded products, and satellite estimates. Further, we conduct LULCC experiments with each LSM to determine if differences in land surface parameters impact the LULCC-induced climate signals. Despite clear deficiencies in surface parameters, all LSMs reasonably capture the spatial pattern and magnitude of near surface temperature and precipitation. However in the LULCC experiments, inaccuracies in the default LSMs result in illogical localized temperature and precipitation climate signals. Differences in thermal climate signals between Noah-MP and CLM-AF indicate that the temperature impacts from LULCC are dependent on the sensitivity of evapotranspiration to LULCC in Sub-Saharan Africa. Errors in land surface parameters indicate that the default WRF LSMs considered are not suitable for LULCC experiments in tropical or Southern Hemisphere regions, and that proficient meteorological model performance can mask these issues. We find CLM-AF to be suitable for use in Sub-Saharan Africa LULCC studies, but more work is needed by the WRF community to improve its applicability to other tropical and Southern Hemisphere climates. }, publisher={Copernicus GmbH}, author={Glotfelty, Timothy and Ramírez-Mejía, Diana and Bowden, Jared and Ghilardi, Adrián and West, J. Jason}, year={2020}, month={Aug} } @article{glotfelty_ramírez-mejía_bowden_ghilardi_west_2020, title={Supplementary material to "Limitations of WRF land surface models for simulating land use and land cover change in Sub-Saharan Africa and development of an improved model (CLM-AF v. 1.0)"}, volume={8}, url={https://doi.org/10.5194/gmd-2020-193-supplement}, DOI={10.5194/gmd-2020-193-supplement}, abstractNote={Addressing Inconsistencies in CLM-AF PFTsIn the savanna category, corn is the fourth most abundant PFT indicating some misclassification with croplands.To eliminate this issue of misclassification, the corn contribution to the savanna category is ignored and the fifth most abundant PFT (broad leaf deciduous tropical trees) is used instead.In the broad leaf evergreen forest category, the third and fourth most abundant PFTs are deciduous tropical and temperate trees.To fix this misclassification, the contributions of each type of deciduous tree are added to their evergreen counterparts (i.e., tropical and temperate) to obtain an appropriate weighted total of tropical to temperate trees.After this, all tropical and temperate trees were assumed to be evergreen to match the MODIS category.In the mosaic cropland category, the fourth most abundant PFT is evenly divided between evergreen and deciduous tropical trees.This is addressed by summing the total deciduous and tropical tree amounts and assuming that all trees within this category were represented by evergreen tropical trees, since most mosaic cropland is in proximity to broadleaf evergreen forests.}, publisher={Copernicus GmbH}, author={Glotfelty, Timothy and Ramírez-Mejía, Diana and Bowden, Jared and Ghilardi, Adrián and West, J. Jason}, year={2020}, month={Aug} } @article{perspective: developing flow policies to balance the water needs of humans and wetlands requires a landscape scale approach inclusive of future scenarios and multiple timescales_2019, url={http://dx.doi.org/10.1007/s13157-019-01184-5}, DOI={10.1007/s13157-019-01184-5}, journal={Wetlands}, year={2019}, month={Jul} } @article{a maieutic exploration of nudging strategies for regional climate applications using the wrf model_2018, url={http://dx.doi.org/10.1175/jamc-d-17-0360.1}, DOI={10.1175/jamc-d-17-0360.1}, abstractNote={Abstract}, journal={Journal of Applied Meteorology and Climatology}, year={2018}, month={Aug} } @book{díaz_gould_álvarez-berríos_aponte-gonzalez_archibald_bowden_carrubba_crespo_fain_gonzález_et al._2018, title={Chapter 20 : US Caribbean. Impacts, Risks, and Adaptation in the United States: The Fourth National Climate Assessment, Volume II}, url={http://dx.doi.org/10.7930/nca4.2018.ch20}, DOI={10.7930/nca4.2018.ch20}, abstractNote={This report is an authoritative assessment of the science of climate change, with a focus on the United States. It represents the second of two volumes of the Fourth National Climate Assessment, mandated by the Global Change Research Act of 1990.}, journal={[]}, institution={U.S. Global Change Research Program}, author={Díaz, Ernesto L. and Gould, William A. and Álvarez-Berríos, Nora and Aponte-Gonzalez, Felix and Archibald, Wayne and Bowden, Jared H. and Carrubba, Lisamarie and Crespo, Wanda and Fain, Stephen J. and González, Grizelle and et al.}, year={2018} } @article{bhardwaj_misra_mishra_wootten_boyles_bowden_terando_2018, title={Downscaling future climate change projections over Puerto Rico using a non-hydrostatic atmospheric model}, volume={147}, ISSN={["1573-1480"]}, url={http://dx.doi.org/10.1007/s10584-017-2130-x}, DOI={10.1007/s10584-017-2130-x}, number={1-2}, journal={CLIMATIC CHANGE}, author={Bhardwaj, Amit and Misra, Vasubandhu and Mishra, Akhilesh and Wootten, Adrienne and Boyles, Ryan and Bowden, J. H. and Terando, Adam J.}, year={2018}, month={Mar}, pages={133–147} } @article{nolte_spero_bowden_mallard_dolwick_2018, title={Supplementary material to "The potential effects of climate change on air quality across the conterminous U.S. at 2030 under three Representative Concentration Pathways (RCPs)"}, volume={6}, url={https://doi.org/10.5194/acp-2018-510-supplement}, DOI={10.5194/acp-2018-510-supplement}, publisher={Copernicus GmbH}, author={Nolte, Christopher G. and Spero, Tanya L. and Bowden, Jared H. and Mallard, Megan S. and Dolwick, Patrick D.}, year={2018}, month={Jun} } @article{nolte_spero_bowden_mallard_dolwick_2018, title={The potential effects of climate change on air quality across the conterminous U.S. at 2030 under three Representative Concentration Pathways (RCPs)}, volume={6}, url={https://doi.org/10.5194/acp-2018-510}, DOI={10.5194/acp-2018-510}, abstractNote={Abstract. The potential impacts of climate change on regional ozone (O3) and fine particulate (PM2.5) air quality in the United States are investigated by downscaling Community Earth System Model (CESM) global climate simulations with the Weather Research and Forecasting (WRF) model, then using the downscaled meteorological fields with the Community Multiscale Air Quality (CMAQ) model. Regional climate and air quality change between 2000 and 2030 under three Representative Concentration Pathways (RCPs) is simulated using 11-year time slices from CESM. The regional climate fields represent historical daily maximum and daily minimum temperatures well, with mean biases less than 2 K for most regions of the U.S. and most seasons of the year and good representation of the variability. Precipitation in the central and eastern U.S. is well simulated for the historical period, with seasonal and annual biases generally less than 25 %, and positive biases in the western U.S. throughout the year and in part of the eastern U.S. during summer. Maximum daily 8-h ozone (MDA8 O3) is projected to increase during summer and autumn in the central and eastern U.S. The increase in summer mean MDA8 O3 is largest under RCP8.5, exceeding 4 ppb in some locations, with smaller seasonal mean increases of up to 2 ppb simulated during autumn and changes during spring generally less than 1 ppb. Increases are magnified at the upper end of the O3 distribution, particularly where projected increases in temperature are greater. Annual average PM2.5 concentration changes range from −1.0 to 1.0 μg m−3. Organic PM2.5 concentrations increase during summer and autumn due to increased biogenic emissions. Decreases in aerosol nitrate occur during winter, accompanied by lesser decreases in ammonium and sulfate, due to warmer temperatures causing increased partitioning to the gas phase. Among meteorological factors examined to account for modeled changes in pollution, temperature and isoprene emissions are found to have the largest changes and the greatest impact on O3 concentrations. }, publisher={Copernicus GmbH}, author={Nolte, Christopher G. and Spero, Tanya L. and Bowden, Jared H. and Mallard, Megan S. and Dolwick, Patrick D.}, year={2018}, month={Jun} } @article{nolte_spero_bowden_mallard_dolwick_2018, title={The potential effects of climate change on air quality across the conterminous US at 2030 under three Representative Concentration Pathways}, volume={18}, ISSN={["1680-7324"]}, url={http://dx.doi.org/10.5194/acp-18-15471-2018}, DOI={10.5194/acp-18-15471-2018}, abstractNote={Abstract. The potential impacts of climate change on regional ozone (O3) and fine particulate (PM2.5) air quality in the United States (US) are investigated by linking global climate simulations with regional-scale meteorological and chemical transport models. Regional climate at 2000 and at 2030 under three Representative Concentration Pathways (RCPs) is simulated by using the Weather Research and Forecasting (WRF) model to downscale 11-year time slices from the Community Earth System Model (CESM). The downscaled meteorology is then used with the Community Multiscale Air Quality (CMAQ) model to simulate air quality during each of these 11-year periods. The analysis isolates the future air quality differences arising from climate-driven changes in meteorological parameters and specific natural emissions sources that are strongly influenced by meteorology. Other factors that will affect future air quality, such as anthropogenic air pollutant emissions and chemical boundary conditions, are unchanged across the simulations. The regional climate fields represent historical daily maximum and daily minimum temperatures well, with mean biases of less than 2 K for most regions of the US and most seasons of the year and good representation of variability. Precipitation in the central and eastern US is well simulated for the historical period, with seasonal and annual biases generally less than 25 %, with positive biases exceeding 25 % in the western US throughout the year and in part of the eastern US during summer. Maximum daily 8 h ozone (MDA8 O3) is projected to increase during summer and autumn in the central and eastern US. The increase in summer mean MDA8 O3 is largest under RCP8.5, exceeding 4 ppb in some locations, with smaller seasonal mean increases of up to 2 ppb simulated during autumn and changes during spring generally less than 1 ppb. Increases are magnified at the upper end of the O3 distribution, particularly where projected increases in temperature are greater. Annual average PM2.5 concentration changes range from −1.0 to 1.0 µg m−3. Organic PM2.5 concentrations increase during summer and autumn due to increased biogenic emissions. Aerosol nitrate decreases during winter, accompanied by lesser decreases in ammonium and sulfate, due to warmer temperatures causing increased partitioning to the gas phase. Among meteorological factors examined to account for modeled changes in pollution, temperature and isoprene emissions are found to have the largest changes and the greatest impact on O3 concentrations. }, number={20}, journal={ATMOSPHERIC CHEMISTRY AND PHYSICS}, publisher={Copernicus GmbH}, author={Nolte, Christopher G. and Spero, Tanya L. and Bowden, Jared H. and Mallard, Megan S. and Dolwick, Patrick D.}, year={2018}, month={Oct}, pages={15471–15489} } @article{zhang_smith_bowden_adelman_west_2017, title={Co-benefits of global, domestic, and sectoral greenhouse gas mitigation for US air quality and human health in 2050}, volume={12}, ISSN={["1748-9326"]}, url={http://dx.doi.org/10.1088/1748-9326/aa8f76}, DOI={10.1088/1748-9326/aa8f76}, abstractNote={Reductions in greenhouse gas (GHG) emissions can bring ancillary benefits of improved air quality and reduced premature mortality, in addition to slowing climate change. Here we study the co-benefits of global and domestic GHG mitigation on US air quality and human health in 2050 at fine resolution using dynamical downscaling of meteorology and air quality from global simulations to the continental US, and quantify for the first time the co-benefits from foreign GHG mitigation. Relative to the reference scenario from which Representative Concentration Pathway 4.5 (RCP4.5) was created, global GHG reductions in RCP4.5 avoid 16 000 PM2.5-related all-cause deaths yr−1 (90% confidence interval, 11 700–20 300), and 8000 (3600–12 400) O3-related respiratory deaths yr−1 in the US in 2050. Foreign GHG mitigation avoids 15% and 62% of PM2.5-and O3-related total avoided deaths, highlighting the importance of foreign mitigation for US health. GHG mitigation in the US residential sector brings the largest co-benefits for PM2.5-related deaths (21% of total domestic co-benefits), and industry for O3 (17%). Monetized benefits for avoided deaths from ozone and PM2.5 are $137 ($87–$187) per ton CO2 at high valuation and $45 ($29–62) at low valuation, of which 31% are from foreign GHG reductions. These benefits likely exceed the marginal cost of GHG reductions in 2050. The US gains significantly greater air quality and health co-benefits when its GHG emission reductions are concurrent with reductions in other nations. Similarly, previous studies estimating co-benefits locally or regionally may greatly underestimate the full co-benefits of coordinated global actions.}, number={11}, journal={ENVIRONMENTAL RESEARCH LETTERS}, author={Zhang, Yuqiang and Smith, Steven J. and Bowden, Jared H. and Adelman, Zachariah and West, J. Jason}, year={2017}, month={Nov} } @article{co-benefits of global and regional greenhouse gas mitigation for us air quality in 2050_2016, url={http://dx.doi.org/10.5194/acp-16-9533-2016}, DOI={10.5194/acp-16-9533-2016}, abstractNote={Abstract. Policies to mitigate greenhouse gas (GHG) emissions will not only slow climate change but can also have ancillary benefits of improved air quality. Here we examine the co-benefits of both global and regional GHG mitigation for US air quality in 2050 at fine resolution, using dynamical downscaling methods, building on a previous global co-benefits study (West et al., 2013). The co-benefits for US air quality are quantified via two mechanisms: through reductions in co-emitted air pollutants from the same sources and by slowing climate change and its influence on air quality, following West et al. (2013). Additionally, we separate the total co-benefits into contributions from domestic GHG mitigation vs. mitigation in foreign countries. We use the Weather Research and Forecasting (WRF) model to dynamically downscale future global climate to the regional scale and the Sparse Matrix Operator Kernel Emissions (SMOKE) program to directly process global anthropogenic emissions to the regional domain, and we provide dynamical boundary conditions from global simulations to the regional Community Multi-scale Air Quality (CMAQ) model. The total co-benefits of global GHG mitigation from the RCP4.5 scenario compared with its reference are estimated to be higher in the eastern US (ranging from 0.6 to 1.0 µg m−3) than the west (0–0.4 µg m−3) for fine particulate matter (PM2.5), with an average of 0.47 µg m−3 over the US; for O3, the total co-benefits are more uniform at 2–5 ppb, with a US average of 3.55 ppb. Comparing the two mechanisms of co-benefits, we find that reductions in co-emitted air pollutants have a much greater influence on both PM2.5 (96 % of the total co-benefits) and O3 (89 % of the total) than the second co-benefits mechanism via slowing climate change, consistent with West et al. (2013). GHG mitigation from foreign countries contributes more to the US O3 reduction (76 % of the total) than that from domestic GHG mitigation only (24 %), highlighting the importance of global methane reductions and the intercontinental transport of air pollutants. For PM2.5, the benefits of domestic GHG control are greater (74 % of total). Since foreign contributions to co-benefits can be substantial, with foreign O3 benefits much larger than those from domestic reductions, previous studies that focus on local or regional co-benefits may greatly underestimate the total co-benefits of global GHG reductions. We conclude that the US can gain significantly greater domestic air quality co-benefits by engaging with other nations to control GHGs. }, journal={Atmospheric Chemistry and Physics}, year={2016}, month={Aug} } @article{the impact of incongruous lake temperatures on regional climate extremes downscaled from the cmip5 archive using the wrf model_2016, url={http://dx.doi.org/10.1175/jcli-d-15-0233.1}, DOI={10.1175/jcli-d-15-0233.1}, abstractNote={Abstract}, journal={Journal of Climate}, year={2016}, month={Jan} } @article{wootten_bowden_boyles_terando_2016, title={The Sensitivity of WRF Downscaled Precipitation in Puerto Rico to Cumulus Parameterization and Interior Grid Nudging}, volume={55}, ISSN={["1558-8432"]}, url={http://dx.doi.org/10.1175/jamc-d-16-0121.1}, DOI={10.1175/jamc-d-16-0121.1}, abstractNote={Abstract}, number={10}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Wootten, A. and Bowden, J. H. and Boyles, R. and Terando, A.}, year={2016}, month={Oct}, pages={2263–2281} } @article{technical challenges and solutions in representing lakes when using wrf in downscaling applications_2015, url={http://dx.doi.org/10.5194/gmd-8-1085-2015}, DOI={10.5194/gmd-8-1085-2015}, abstractNote={Abstract. The Weather Research and Forecasting (WRF) model is commonly used to make high-resolution future projections of regional climate by downscaling global climate model (GCM) outputs. Because the GCM fields are typically at a much coarser spatial resolution than the target regional downscaled fields, lakes are often poorly resolved in the driving global fields, if they are resolved at all. In such an application, using WRF's default interpolation methods can result in unrealistic lake temperatures and ice cover at inland water points. Prior studies have shown that lake temperatures and ice cover impact the simulation of other surface variables, such as air temperatures and precipitation, two fields that are often used in regional climate applications to understand the impacts of climate change on human health and the environment. Here, alternative methods for setting lake surface variables in WRF for downscaling simulations are presented and contrasted. }, journal={Geoscientific Model Development}, year={2015}, month={Apr} } @article{improving the representation of clouds, radiation, and precipitation using spectral nudging in the weather research and forecasting model_2014, url={http://dx.doi.org/10.1002/2014jd022173}, DOI={10.1002/2014jd022173}, abstractNote={Spectral nudging—a scale‐selective interior constraint technique—is commonly used in regional climate models to maintain consistency with large‐scale forcing while permitting mesoscale features to develop in the downscaled simulations. Several studies have demonstrated that spectral nudging improves the representation of regional climate in reanalysis‐forced simulations compared with not using nudging in the interior of the domain. However, in the Weather Research and Forecasting (WRF) model, spectral nudging tends to produce degraded precipitation simulations when compared to analysis nudging—an interior constraint technique that is scale indiscriminate but also operates on moisture fields which until now could not be altered directly by spectral nudging. Since analysis nudging is less desirable for regional climate modeling because it dampens fine‐scale variability, changes are proposed to the spectral nudging methodology to capitalize on differences between the nudging techniques and aim to improve the representation of clouds, radiation, and precipitation without compromising other fields. These changes include adding spectral nudging toward moisture, limiting nudging to below the tropopause, and increasing the nudging time scale for potential temperature, all of which collectively improve the representation of mean and extreme precipitation, 2 m temperature, clouds, and radiation, as demonstrated using a model‐simulated 20 year historical period. Such improvements to WRF may increase the fidelity of regional climate data used to assess the potential impacts of climate change on human health and the environment and aid in climate change mitigation and adaptation studies.}, journal={Journal of Geophysical Research: Atmospheres}, year={2014}, month={Oct} } @article{regional climate variations and change for terrestrial ecosystems workshop review_2014, url={http://dx.doi.org/10.1890/0012-9623-95.1.96}, DOI={10.1890/0012-9623-95.1.96}, abstractNote={North Carolina State University, the University of North Carolina at Chapel Hill, and the U.S. Environmental Protection Agency, in partnership with the U.S. Department of the Interior Southeast Climate Science Center (SECSC), hosted the Regional Climate Variations and Change for Terrestrial Ecosystems Workshop. The workshop was held at North Carolina State University in Raleigh on 16–17 May 2013. The workshop assembled ~40 climate and ecosystem scientists to discuss challenges and uncertainties of understanding the interactions of climate and ecosystems across the Carolinas. This multidisciplinary effort sought to bridge the knowledge gap between climate and ecosystems scientists. Another objective of this workshop was to identify climate-related variables that can be used to evaluate projections of climate change for the ecology community in the Carolinas. This workshop was the first in the Carolinas to engage both disciplines to discuss the needs of the ecology community with regard to regional projections of climate change. The workshop facilitated a discussion of the needs of ecologists from the regional projections of climate change, and the abilities and limitations of these projections, with guidance for appropriate use of projection information.}, journal={Bulletin of the Ecological Society of America}, year={2014}, month={Jan} } @article{simulating the impact of the large-scale circulation on the 2-m temperature and precipitation climatology_2013, url={http://dx.doi.org/10.1007/s00382-012-1440-y}, DOI={10.1007/s00382-012-1440-y}, journal={Climate Dynamics}, year={2013}, month={Apr} } @article{does nudging squelch the extremes in regional climate modeling?_2012, url={http://dx.doi.org/10.1175/jcli-d-12-00048.1}, DOI={10.1175/jcli-d-12-00048.1}, abstractNote={Abstract}, journal={Journal of Climate}, year={2012}, month={Oct} } @article{examining interior grid nudging techniques using two-way nesting in the wrf model for regional climate modeling_2012, url={http://dx.doi.org/10.1175/jcli-d-11-00167.1}, DOI={10.1175/jcli-d-11-00167.1}, abstractNote={Abstract}, journal={Journal of Climate}, year={2012}, month={Apr} } @article{davis_bowden_semazzi_xie_onol_2009, title={Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain}, volume={22}, ISSN={["1520-0442"]}, url={http://dx.doi.org/10.1175/2009jcli2388.1}, DOI={10.1175/2009JCLI2388.1}, abstractNote={Abstract}, number={13}, journal={JOURNAL OF CLIMATE}, author={Davis, Neil and Bowden, Jared and Semazzi, Fredrick and Xie, Lian and Onol, Baris}, year={2009}, month={Jul}, pages={3595–3616} } @article{bowden_semazzi_2007, title={Empirical analysis of intraseasonal climate variability over the greater horn of Africa}, volume={20}, ISSN={["1520-0442"]}, url={http://dx.doi.org/10.1175/2007jcli1587.1}, DOI={10.1175/2007JCLI1587.1}, abstractNote={Abstract}, number={23}, journal={JOURNAL OF CLIMATE}, author={Bowden, Jared H. and Semazzi, Fredrick H. M.}, year={2007}, month={Dec}, pages={5715–5731} } @article{fall_semazzi_dutta_niyogi_anyah_bowden_2006, title={The spatiotemporal climate variability over Senegal and its relationship to global climate}, volume={26}, ISSN={["1097-0088"]}, url={http://dx.doi.org/10.1002/joc.1355}, DOI={10.1002/joc.1355}, abstractNote={Abstract}, number={14}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Fall, Souleymane and Semazzi, Fredrick H. M. and Dutta, Dev and Niyogi, S. and Anyah, Richard O. and Bowden, Jared}, year={2006}, month={Nov}, pages={2057–2076} }