@misc{schlef_kunkel_brown_demissie_lettenmaier_wagner_wigmosta_karl_easterling_wang_et al._2023, title={Incorporating non-stationarity from climate change into rainfall frequency and intensity-duration-frequency (IDF) curves}, volume={616}, ISSN={["1879-2707"]}, DOI={10.1016/j.jhydrol.2022.128757}, abstractNote={Intensity-duration-frequency (IDF) curves – sometimes also called precipitation frequency estimates – are used to design urban drainage systems for stormwater control and, when combined with hydrologic modeling, to design flood control infrastructure and other structures. However, common approaches to estimating IDF curves need to be revised to account for non-stationarity from global climate change. This review synthesizes the current knowledge and on-going research regarding IDF curves under non-stationarity. In particular, this review briefly summarizes known and projected changes in extreme precipitation at the global scale, describes approaches for IDF curve estimation under non-stationarity (focusing on the covariate-based approach and including a brief overview of the specific challenges facing snow-dominated regions), addresses the topic of regionalization under non-stationarity (which has been overlooked in previous reviews), explores the challenges of design values and uncertainty in the context of non-stationarity, provides details on these topics in the context of the United States, and finishes by enumerating needed avenues of future research.}, journal={JOURNAL OF HYDROLOGY}, author={Schlef, Katherine E. and Kunkel, Kenneth E. and Brown, Casey and Demissie, Yonas and Lettenmaier, Dennis P. and Wagner, Anna and Wigmosta, Mark S. and Karl, Thomas R. and Easterling, David R. and Wang, Kimberly J. and et al.}, year={2023}, month={Jan} } @article{crossett_dupigny-giroux_kunkel_betts_bomblies_2023, title={Synoptic Typing of Multiduration, Heavy Precipitation Records in the Northeastern United States: 1895-2017}, volume={62}, ISSN={["1558-8432"]}, DOI={10.1175/JAMC-D-22-0091.1}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Crossett, Caitlin C. and Dupigny-Giroux, Lesley-Ann L. and Kunkel, Kenneth E. and Betts, Alan K. and Bomblies, Arne}, year={2023}, month={Jun}, pages={721–736} } @article{eischeid_hoerling_quan_kumar_barsugli_labe_kunkel_schreck iii_easterling_zhang_et al._2023, title={Why Has the Summertime Central US Warming Hole Not Disappeared?}, volume={36}, ISSN={["1520-0442"]}, DOI={10.1175/JCLI-D-22-0716.1}, abstractNote={Abstract}, number={20}, journal={JOURNAL OF CLIMATE}, author={Eischeid, J. K. and Hoerling, M. P. and Quan, X. -w. and Kumar, A. and Barsugli, J. and Labe, Z. M. and Kunkel, K. E. and Schreck III, C. J. and Easterling, D. R. and Zhang, T. and et al.}, year={2023}, month={Oct}, pages={7319–7336} } @article{barsugli_easterling_arndt_coates_delworth_hoerling_johnson_kapnick_kumar_kunkel_et al._2022, title={Development of a Rapid Response Capability to Evaluate Causes of Extreme Temperature and Drought Events in the United States}, volume={103}, ISSN={["1520-0477"]}, DOI={10.1175/BAMS-D-21-0237.1}, abstractNote={In January 2021 work began on a NOAA Climate Program Office funded project “that develops and tests a potential rapid event analysis and assessment capability” (NOAA Climate Program Office 2020). This 3.5–yr effort brings together scientists from four NOAA Laboratories/Centers and university scientists at two of NOAA’s Cooperative Institutes. This funded project has two high-level goals: 1) to address outstanding dataset, model, and methodological gaps in explaining extreme events within a changing climate, and 2) to build a prototype rapid event attribution system for temperature-related and drought extremes that could eventually serve routine climate information needs at local, state, and regional levels. The focus on temperature-related extremes derives from the conclusions of the U.S. National Academy of Sciences report that confidence in attribution findings is greatest for this class of extremes (National Academies of Sciences Engineering and Medicine 2016). The project will leverage additional research projects that were funded under the same call that focus on the underlying mechanisms for these types of extreme events. Several climate trends in the United States present challenges for the attribution of temperature-related extremes (Fig. 1). The first is the lack of appreciable Joseph J. Barsugli, David R. Easterling, Derek S. Arndt, David A. Coates, Thomas L. Delworth, Martin P. Hoerling, Nathaniel Johnson, Sarah B. Kapnick, Arun Kumar, Kenneth E. Kunkel,Carl J. Schreck, Russell S. Vose, and Tao Zhang}, number={3}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Barsugli, Joseph J. and Easterling, David R. and Arndt, Derek S. and Coates, David A. and Delworth, Thomas L. and Hoerling, Martin P. and Johnson, Nathaniel and Kapnick, Sarah B. and Kumar, Arun and Kunkel, Kenneth E. and et al.}, year={2022}, month={Mar}, pages={S14–S20} } @article{kunkel_yin_sun_champion_stevens_johnson_2022, title={Extreme Precipitation Trends and Meteorological Causes Over the Laurentian Great Lakes}, volume={4}, ISSN={["2624-9375"]}, DOI={10.3389/frwa.2022.804799}, abstractNote={Trends in extreme precipitation and their causes were analyzed for events within the Laurentian Great Lakes for several periods: 1908–2020, 1949–2020, 1980–2019, and 1980–2020. Upward trends in extreme precipitation were found for multiple metrics, including the number of exceedances of return period thresholds for several durations and average recurrence intervals (ARI), the number of extreme basin-average 4-day precipitation totals, and the annual maximum daily station precipitation. The causes of extreme events were classified into 5 meteorological categories: fronts of extratropical cyclones (ETC-FRT), extratropical cyclones but not proximate to the fronts (ETC-NFRT), mesoscale convective systems (MCS), tropical cyclones (TC), and air mass convection (AMC). For daily events exceeding the threshold for 5-yr ARI, ETC-FRTs account for 78% of all events, followed by ETC-NFRTs (12%), MCSs (6%), TCs (2%), and AMC (1%). Upward trends in the number of events by cause were found for all categories except AMC. An examination of basin-wide 4-day extreme events (40 largest events during 1980–2019) found that all events were caused by ETC-FRTs (85%) or ETC-NFRTs (15%).}, journal={FRONTIERS IN WATER}, author={Kunkel, Kenneth E. and Yin, Xungang and Sun, Liqiang and Champion, Sarah M. and Stevens, Laura E. and Johnson, Katharine M.}, year={2022}, month={May} } @article{dagon_truesdale_biard_kunkel_meehl_molina_2022, title={Machine Learning-Based Detection of Weather Fronts and Associated Extreme Precipitation in Historical and Future Climates}, volume={127}, ISSN={["2169-8996"]}, DOI={10.1029/2022JD037038}, abstractNote={Abstract}, number={21}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Dagon, Katherine and Truesdale, John and Biard, James C. and Kunkel, Kenneth E. and Meehl, Gerald A. and Molina, Maria J.}, year={2022}, month={Nov} } @article{shiva_chandler_kunkel_2022, title={Mapping Heat Wave Hazard in Urban Areas: A Novel Multi-Criteria Decision Making Approach}, volume={13}, ISSN={["2073-4433"]}, DOI={10.3390/atmos13071037}, abstractNote={Global population is experiencing more frequent, longer, and more severe heat waves due to global warming and urbanization. Episodic heat waves increase mortality and morbidity rates and demands for water and energy. Urban managers typically assess heat wave risk based on heat wave hazard, population exposure, and vulnerability, with a general assumption of spatial uniformity of heat wave hazard. We present a novel analysis that demonstrates an approach to determine the spatial distribution of a set of heat wave properties and hazard. The analysis is based on the Livneh dataset at a 1/16-degree resolution from 1950 to 2009 in Maricopa County, Arizona, USA. We then focused on neighborhoods with the most frequent, severe, earlier, and extended periods of heat wave occurrences. On average, the first heat wave occurs 40 days earlier in the eastern part of the county; the northeast part of this region experiences 12 days further extreme hot days and 30 days longer heat wave season than other regions of the area. Then, we applied a multi-criteria decision-making (MCDM) tool (TOPSIS) to evaluate the total hazard posed by heat wave components. We found that the northern and central parts of the metropolitan area are subject to the greatest heat wave hazard and that individual heat wave hazard components did not necessarily indicate heat hazard. This approach is intended to support local government planning for heat wave adaptation and mitigation strategies, where cooling centers, heat emergency water distribution networks, and electrical energy delivery can be targeted based on current and projected local heat wave characteristics.}, number={7}, journal={ATMOSPHERE}, author={Shiva, Javad Shafiei and Chandler, David G. and Kunkel, Kenneth E.}, year={2022}, month={Jul} } @article{dong_wang_kunkel_shao_xing_wei_2021, title={Heterogeneous response of global precipitation concentration to global warming}, volume={41}, ISSN={["1097-0088"]}, DOI={10.1002/joc.6851}, abstractNote={Abstract}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Dong, Qing and Wang, Weiguang and Kunkel, Kenneth E. and Shao, Quanxi and Xing, Wanqiu and Wei, Jia}, year={2021}, month={Jan}, pages={E2347–E2359} } @article{russell_risser_smith_kunkel_2020, title={Investigating the association between late spring Gulf of Mexico sea surface temperatures and US Gulf Coast precipitation extremes with focus on Hurricane Harvey}, volume={31}, ISSN={["1099-095X"]}, DOI={10.1002/env.2595}, abstractNote={Abstract}, number={2}, journal={ENVIRONMETRICS}, author={Russell, Brook T. and Risser, Mark D. and Smith, Richard L. and Kunkel, Kenneth E.}, year={2020}, month={Mar} } @article{kunkel_stevens_stevens_karl_2020, title={Observed Climatological Relationships of Extreme Daily Precipitation Events With Precipitable Water and Vertical Velocity in the Contiguous United States}, volume={47}, ISSN={["1944-8007"]}, DOI={10.1029/2019GL086721}, abstractNote={Abstract}, number={12}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Kunkel, Kenneth E. and Stevens, Scott E. and Stevens, Laura E. and Karl, Thomas R.}, year={2020}, month={Jun} } @article{kunkel_karl_squires_yin_stegall_easterling_2020, title={Precipitation Extremes: Trends and Relationships with Average Precipitation and Precipitable Water in the Contiguous United States}, volume={59}, ISSN={["1558-8432"]}, DOI={10.1175/JAMC-D-19-0185.1}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Kunkel, Kenneth E. and Karl, Thomas R. and Squires, Michael F. and Yin, Xungang and Stegall, Steve T. and Easterling, David R.}, year={2020}, month={Jan}, pages={125–142} } @article{kunkel_champion_2019, title={An Assessment of Rainfall from Hurricanes Harvey and Florence Relative to Other Extremely Wet Storms in the United States}, volume={46}, ISSN={["1944-8007"]}, DOI={10.1029/2019GL085034}, abstractNote={Abstract}, number={22}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Kunkel, Kenneth E. and Champion, Sarah M.}, year={2019}, month={Nov}, pages={13500–13506} } @article{rennie_bell_kunkel_herring_cullen_abadi_2019, title={Development of a Submonthly Temperature Product to Monitor Near-Real-Time Climate Conditions and Assess Long-Term Heat Events in the United States}, volume={58}, ISSN={["1558-8432"]}, DOI={10.1175/JAMC-D-19-0076.1}, abstractNote={Abstract}, number={12}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Rennie, Jared and Bell, Jesse E. and Kunkel, Kenneth E. and Herring, Stephanie and Cullen, Heidi and Abadi, Azar M.}, year={2019}, month={Dec}, pages={2653–2674} } @article{lee_waliser_lee_loikith_kunkel_2019, title={Evaluation of CMIP5 ability to reproduce twentieth century regional trends in surface air temperature and precipitation over CONUS}, volume={53}, ISSN={["1432-0894"]}, DOI={10.1007/s00382-019-04875-1}, number={9-10}, journal={CLIMATE DYNAMICS}, author={Lee, Jinny and Waliser, Duane and Lee, Huikyo and Loikith, Paul and Kunkel, Kenneth E.}, year={2019}, month={Nov}, pages={5459–5480} } @article{shiva_chandler_kunkel_2019, title={Localized Changes in Heat Wave Properties Across the United States}, volume={7}, ISSN={["2328-4277"]}, DOI={10.1029/2018EF001085}, abstractNote={Abstract}, number={3}, journal={EARTHS FUTURE}, author={Shiva, Javad Shafiei and Chandler, David G. and Kunkel, Kenneth E.}, year={2019}, month={Mar}, pages={300–319} } @article{stevens_schreck_saha_bell_kunkel_2019, title={Precipitation and Fatal Motor Vehicle Crashes: Continental Analysis with High-Resolution Radar Data}, volume={100}, ISSN={["1520-0477"]}, DOI={10.1175/BAMS-D-18-0001.1}, abstractNote={Abstract}, number={8}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Stevens, Scott E. and Schreck, Carl J., III and Saha, Shubhayu and Bell, Jesse E. and Kunkel, Kenneth E.}, year={2019}, month={Aug}, pages={1453–1462} } @article{stegall_kunkel_2019, title={Simulation of Daily Extreme Precipitation over the United States in the CMIP5 30-Yr Decadal Prediction Experiment}, volume={58}, ISSN={["1558-8432"]}, DOI={10.1175/JAMC-D-18-0057.1}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Stegall, Steve T. and Kunkel, Kenneth E.}, year={2019}, month={Apr}, pages={875–886} } @misc{bell_brown_conlon_herring_kunkel_lawrimore_luber_schreck_smith_uejio_2018, title={Changes in extreme events and the potential impacts on human health}, volume={68}, ISSN={["2162-2906"]}, DOI={10.1080/10962247.2017.1401017}, abstractNote={ABSTRACT Extreme weather and climate-related events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, dust storms, flooding rains, coastal flooding, storm surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden. More information is needed about the impacts of climate change on public health and economies to effectively plan for and adapt to climate change. This paper describes some of the ways extreme events are changing and provides examples of the potential impacts on human health and infrastructure. It also identifies key research gaps to be addressed to improve the resilience of public health to extreme events in the future. Implications: Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, flooding rains, coastal flooding, surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden.}, number={4}, journal={JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION}, author={Bell, Jesse E. and Brown, Claudia Langford and Conlon, Kathryn and Herring, Stephanie and Kunkel, Kenneth E. and Lawrimore, Jay and Luber, George and Schreck, Carl and Smith, Adam and Uejio, Christopher}, year={2018}, pages={265–287} } @article{hallar_molotch_hand_livneh_mccubbin_petersen_michalsky_lowenthal_kunkel_2017, title={Impacts of increasing aridity and wildfires on aerosol loading in the intermountain Western US}, volume={12}, ISSN={["1748-9326"]}, DOI={10.1088/1748-9326/aa510a}, abstractNote={Feedbacks between climate warming, land surface aridity, and wildfire-derived aerosols represent a large source of uncertainty in future climate predictions. Here, long-term observations of aerosol optical depth, surface level aerosol loading, fire-area burned, and hydrologic simulations are used to show that regional-scale increases in aridity and resulting wildfires have significantly increased summertime aerosol loading in remote high elevation regions of the Intermountain West of the United States. Surface summertime organic aerosol loading and total aerosol optical depth were both strongly correlated (p < 0.05) with aridity and fire area burned at high elevation sites across major western US mountain ranges. These results demonstrate that surface-level organic aerosol loading is dominated by summertime wildfires at many high elevation sites. This analysis provides new constraints for climate projections on the influence of drought and resulting wildfires on aerosol loading. These empirical observations will help better constrain projected increases in organic aerosol loading with increased fire activity under climate change.}, number={1}, journal={ENVIRONMENTAL RESEARCH LETTERS}, author={Hallar, A. Gannet and Molotch, Noah P. and Hand, Jenny L. and Livneh, Ben and McCubbin, Ian B. and Petersen, Ross and Michalsky, Joseph and Lowenthal, Douglas and Kunkel, Kenneth E.}, year={2017}, month={Jan} } @article{bhowmik_sankarasubramanian_sinha_patskoski_mahinthakumar_kunkel_2017, title={Multivariate Downscaling Approach Preserving Cross Correlations across Climate Variables for Projecting Hydrologic Fluxes}, volume={18}, ISSN={1525-755X 1525-7541}, url={http://dx.doi.org/10.1175/JHM-D-16-0160.1}, DOI={10.1175/jhm-d-16-0160.1}, abstractNote={Abstract}, number={8}, journal={Journal of Hydrometeorology}, publisher={American Meteorological Society}, author={Bhowmik, Rajarshi Das and Sankarasubramanian, A. and Sinha, Tushar and Patskoski, Jason and Mahinthakumar, G. and Kunkel, Kenneth E.}, year={2017}, month={Aug}, pages={2187–2205} } @article{sankarasubramanian_sabo_larson_seo_sinha_bhowmik_vidal_kunkel_mahinthakumar_berglund_et al._2017, title={Synthesis of public water supply use in the United States: Spatio‐temporal patterns and socio‐economic controls}, volume={5}, ISSN={2328-4277 2328-4277}, url={http://dx.doi.org/10.1002/2016EF000511}, DOI={10.1002/2016ef000511}, abstractNote={Abstract}, number={7}, journal={Earth's Future}, publisher={American Geophysical Union (AGU)}, author={Sankarasubramanian, A. and Sabo, J. L. and Larson, K. L. and Seo, S. B. and Sinha, T. and Bhowmik, R. and Vidal, A. Ruhi and Kunkel, K. and Mahinthakumar, G. and Berglund, E. Z. and et al.}, year={2017}, month={Jul}, pages={771–788} } @article{easterling_kunkel_wehner_sun_2016, title={Detection and attribution of climate extremes in the observed record}, volume={11}, ISSN={2212-0947}, url={http://dx.doi.org/10.1016/J.WACE.2016.01.001}, DOI={10.1016/J.WACE.2016.01.001}, abstractNote={We present an overview of practices and challenges related to the detection and attribution of observed changes in climate extremes. Detection is the identification of a statistically significant change in the extreme values of a climate variable over some period of time. Issues in detection discussed include data quality, coverage, and completeness. Attribution takes that detection of a change and uses climate model simulations to evaluate whether a cause can be assigned to that change. Additionally, we discuss a newer field of attribution, event attribution, where individual extreme events are analyzed for the express purpose of assigning some measure of whether that event was directly influenced by anthropogenic forcing of the climate system.}, journal={Weather and Climate Extremes}, publisher={Elsevier BV}, author={Easterling, David R. and Kunkel, Kenneth E. and Wehner, Michael F. and Sun, Liqiang}, year={2016}, month={Mar}, pages={17–27} } @article{paquin_frigon_kunkel_2016, title={Evaluation of Total Precipitable Water from CRCM4 using the NVAP-MEaSUREs Dataset and ERA-Interim Reanalysis Data}, volume={54}, ISSN={["1480-9214"]}, DOI={10.1080/07055900.2016.1230043}, abstractNote={Abstract The fourth-generation Canadian Regional Climate Model’s (CRCM4) precipitable water is evaluated and compared with observational data and ERA-Interim reanalysis data over five Canadian basins with simulations driven by ERA-Interim (two) and global climate models (two). Considering the 22 years of data available in the observations, we analyze precipitable water’s behaviour through its annual cycle, its daily distribution, and its annual daily maxima. For the simulations driven by reanalyses, differences in annual daily maximum values and their correlations with observations are examined. In general, the values for precipitable water simulated by CRCM4 are similar to those observed, and the model reproduces both the interannual and inter-basin variabilities. The simulation at 15 km resolution produces higher extreme values than simulations performed at 45 km resolution and higher than the observations taken at coarser resolution (1°), without much influence on the mean behaviour. Some underestimation is found with the simulation driven by the Canadian Centre for Climate Modelling and Analysis Model, version 3, a sign of a cold and dry bias, whereas the run driven by the European Centre Hamburg Model, version 5, is much closer to the observations, pointing to the importance of closely considering the regional–global model combination. Overall, CRCM4's ability to reproduce the major characteristics of observed precipitable water makes it a possible tool for providing precipitable water data that could serve as a basis for probable maximum precipitation and probable maximum flood studies at the basin scale.}, number={5}, journal={ATMOSPHERE-OCEAN}, author={Paquin, D. and Frigon, A. and Kunkel, K. E.}, year={2016}, month={Dec}, pages={541–548} } @article{waple_champion_kunkel_tilmes_2016, title={Innovations in information management and access for assessments}, volume={135}, DOI={10.1007/s10584-015-1588-7}, abstractNote={The third National Climate Assessment (NCA3) included goals for becoming a more timely, inclusive, rigorous, and sustained process, and for serving a wider variety of decision makers. In order to accomplish these goals, it was necessary to deliberately design an information management strategy that could serve multiple stakeholders and manage different types of information - from highly mature government-supported climate science data, to isolated practitioner-generated case study information - and to do so in ways that are consistent and appropriate for a highly influential assessment. Meeting the information management challenge for NCA3 meant balancing relevance and authority, complexity and accessibility, inclusivity and rigor. Increasing traceability of data behind figures and graphics, designing a public-facing website, managing hundreds of technical inputs to the NCA, and producing guidance for over 300 participants on meeting the Information Quality Act were all aspects of a deliberate, multi-faceted, and strategic information management approach that nonetheless attempted to be practical and usable for a variety of participants and stakeholders.}, number={1}, journal={Climatic Change}, author={Waple, A. M. and Champion, S. M. and Kunkel, K. E. and Tilmes, C.}, year={2016}, pages={69–83} } @article{kunkel_moss_parris_2016, title={Innovations in science and scenarios for assessment}, volume={135}, ISSN={["1573-1480"]}, DOI={10.1007/s10584-015-1494-z}, abstractNote={Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.}, number={1}, journal={CLIMATIC CHANGE}, author={Kunkel, Kenneth E. and Moss, Richard and Parris, Adam}, year={2016}, month={Mar}, pages={55–68} } @article{janssen_sriver_wuebbles_kunkel_2016, title={Seasonal and regional variations in extreme precipitation event frequency using CMIP5}, volume={43}, ISSN={["1944-8007"]}, DOI={10.1002/2016gl069151}, abstractNote={Abstract}, number={10}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Janssen, E. and Sriver, R. L. and Wuebbles, D. J. and Kunkel, K. E.}, year={2016}, month={May}, pages={5385–5393} } @article{kunkel_robinson_champion_yin_estilow_frankson_2016, title={Trends and Extremes in Northern Hemisphere Snow Characteristics}, volume={2}, ISSN={2198-6061}, url={http://dx.doi.org/10.1007/S40641-016-0036-8}, DOI={10.1007/S40641-016-0036-8}, abstractNote={Recent studies of snow climatology show a mix of trends but a preponderance of evidence suggest an overall tendency toward decreases in several metrics of snow extremes. The analysis performed herein on maximum seasonal snow depth points to a robust negative trend in this variable for the period of winter 1960/1961–winter 2014/2015. This conclusion is applicable to North America. Maximum snow depth is also mostly decreasing for those European stations analyzed. Research studies show generally negative trends in snow cover extent and snow water equivalent across both North America and Eurasia. These results are mostly, but not fully, consistent with simple hypotheses for the effects of global warming on snow characteristics.}, number={2}, journal={Current Climate Change Reports}, publisher={Springer Science and Business Media LLC}, author={Kunkel, Kenneth E. and Robinson, David A. and Champion, Sarah and Yin, Xungang and Estilow, Thomas and Frankson, Rebekah M.}, year={2016}, month={Apr}, pages={65–73} } @article{jacobs_moore_kunkel_sun_2015, title={A framework for examining climate-driven changes to the seasonality and geographical range of coastal pathogens and harmful algae}, volume={8}, ISSN={2212-0963}, url={http://dx.doi.org/10.1016/J.CRM.2015.03.002}, DOI={10.1016/J.CRM.2015.03.002}, abstractNote={Climate change is expected to alter coastal ecosystems in ways which may have predictable consequences for the seasonality and geographical distribution of human pathogens and harmful algae. Here we demonstrate relatively simple approaches for evaluating the risk of occurrence of pathogenic bacteria in the genus Vibrio and outbreaks of toxin-producing harmful algae in the genus Alexandrium, with estimates of uncertainty, in U.S. coastal waters under future climate change scenarios through the end of the 21st century. One approach forces empirical models of growth, abundance and the probability of occurrence of the pathogens and algae at specific locations in the Chesapeake Bay and Puget Sound with ensembles of statistically downscaled climate model projections to produce first order assessments of changes in seasonality. In all of the case studies examined, the seasonal window of occurrence for Vibrio and Alexandrium broadened, indicating longer annual periods of time when there is increased risk for outbreaks. A second approach uses climate model projections coupled with GIS to identify the potential for geographic range shifts for Vibrio spp. in the coastal waters of Alaska. These two approaches could be applied to other coastal pathogens that have climate sensitive drivers to investigate potential changes to the risk of outbreaks in both time (seasonality) and space (geographical distribution) under future climate change scenarios.}, journal={Climate Risk Management}, publisher={Elsevier BV}, author={Jacobs, John and Moore, Stephanie K. and Kunkel, Kenneth E. and Sun, Liqiang}, year={2015}, pages={16–27} } @article{kibler_tester_kunkel_moore_litaker_2015, title={Effects of ocean warming on growth and distribution of dinoflagellates associated with ciguatera fish poisoning in the Caribbean}, volume={316}, ISSN={["1872-7026"]}, DOI={10.1016/j.ecolmodel.2015.08.020}, abstractNote={Projected water temperatures at six sites in the Gulf of Mexico and Caribbean Sea were used to forecast potential effects of climate change on the growth, abundance and distribution of Gambierdiscus and Fukuyoa species, dinoflagellates associated with ciguatera fish poisoning (CFP). Data from six sites in the Greater Caribbean were used to create statistically downscaled projections of water temperature using an ensemble of eleven global climate models and simulation RCP6.0 from the WCRP Coupled Model Intercomparison Project Phase 5 (CMIP5). Growth rates of five dinoflagellate species were estimated through the end of the 21st century using experimentally derived temperature vs. growth relationships for multiple strains of each species. The projected growth rates suggest the distribution and abundance of CFP-associated dinoflagellate species will shift substantially through 2099. Rising water temperatures are projected to increase the abundance and diversity of Gambierdiscus and Fukuyoa species in the Gulf of Mexico and along the U.S. southeast Atlantic coast. In the Caribbean Sea, where the highest average temperatures correlate with the highest rates of CFP, it is projected that Gambierdiscus caribaeus, Gambierdiscus belizeanus and Fukuyoa ruetzleri will become increasingly dominant. Conversely, the lower temperature-adapted species Gambierdiscus carolinianus and Gambierdiscus ribotype 2 are likely to become less prevalent in the Caribbean Sea and are expected to expand their ranges in the northern Gulf of Mexico and farther into the western Atlantic. The risks associated with CFP are also expected to change regionally, with higher incidence rates in the Gulf of Mexico and U.S. southeast Atlantic coast, with stable or slightly lower risks in the Caribbean Sea.}, journal={ECOLOGICAL MODELLING}, author={Kibler, Steven R. and Tester, Patricia A. and Kunkel, Kenneth E. and Moore, Stephanie K. and Litaker, R. Wayne}, year={2015}, month={Nov}, pages={194–210} } @article{kunkel_vose_stevens_knight_2015, title={Is the monthly temperature climate of the United States becoming more extreme?}, volume={42}, ISSN={["1944-8007"]}, DOI={10.1002/2014gl062035}, abstractNote={Abstract}, number={2}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Kunkel, Kenneth E. and Vose, Russell S. and Stevens, Laura E. and Knight, Richard W.}, year={2015}, month={Jan}, pages={629–636} } @misc{kossin_karl_knutson_emanuel_kunkel_o'brien_2015, title={Reply to "Comments on 'Monitoring and Understanding Trends in Extreme Storms: State of Knowledge'"}, volume={96}, ISSN={["1520-0477"]}, DOI={10.1175/bams-d-14-00261.1}, abstractNote={look up definitions online any time, any place, anywhere.}, number={7}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Kossin, James P. and Karl, Thomas R. and Knutson, Thomas R. and Emanuel, Kerry A. and Kunkel, Kenneth E. and O'Brien, James J.}, year={2015}, month={Jul} } @article{frei_kunkel_matonse_2015, title={The Seasonal Nature of Extreme Hydrological Events in the Northeastern United States}, volume={16}, ISSN={["1525-7541"]}, DOI={10.1175/jhm-d-14-0237.1}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF HYDROMETEOROLOGY}, author={Frei, Allan and Kunkel, Kenneth E. and Matonse, Adao}, year={2015}, month={Oct}, pages={2065–2085} } @article{janssen_wuebbles_kunkel_olsen_goodman_2014, title={Observational- and model-based trends and projections of extreme precipitation over the contiguous United States}, volume={2}, ISSN={2328-4277}, url={http://dx.doi.org/10.1002/2013EF000185}, DOI={10.1002/2013EF000185}, abstractNote={Abstract}, number={2}, journal={Earth's Future}, publisher={American Geophysical Union (AGU)}, author={Janssen, Emily and Wuebbles, Donald J. and Kunkel, Kenneth E. and Olsen, Seth C. and Goodman, Alex}, year={2014}, month={Feb}, pages={99–113} } @article{peterson_karl_kossin_kunkel_lawrimore_mcmahon_vose_yin_2013, title={Changes in weather and climate extremes: State of knowledge relevant to air and water quality in the United States}, volume={64}, ISSN={1096-2247 2162-2906}, url={http://dx.doi.org/10.1080/10962247.2013.851044}, DOI={10.1080/10962247.2013.851044}, abstractNote={Air and water quality are impacted by extreme weather and climate events on time scales ranging from minutes to many months. This review paper discusses the state of knowledge of how and why extreme events are changing and are projected to change in the future. These events include heat waves, cold waves, floods, droughts, hurricanes, strong extratropical cyclones such as nor'easters, heavy rain, and major snowfalls. Some of these events, such as heat waves, are projected to increase, while others, with cold waves being a good example, will decrease in intensity in our warming world. Each extreme's impact on air or water quality can be complex and can even vary over the course of the event. Implications: Because extreme weather and climate events impact air and water quality, understanding how the various extremes are changing and are projected to change in the future has ramifications on air and water quality management.}, number={2}, journal={Journal of the Air & Waste Management Association}, publisher={Informa UK Limited}, author={Peterson, Thomas C. and Karl, Thomas R. and Kossin, James P. and Kunkel, Kenneth E. and Lawrimore, Jay H. and McMahon, James R. and Vose, Russell S. and Yin, Xungang}, year={2013}, month={Oct}, pages={184–197} } @article{kunkel_karl_brooks_kossin_lawrimore_arndt_bosart_changnon_cutter_doesken_et al._2013, title={Monitoring and understanding trends in extreme storms state of knowledge}, volume={94}, number={4}, journal={Bulletin of the American Meteorological Society}, author={Kunkel, K. E. and Karl, T. R. and Brooks, H. and Kossin, J. and Lawrimore, J. H. and Arndt, D. and Bosart, L. and Changnon, D. and Cutter, S. L. and Doesken, N. and et al.}, year={2013}, pages={499–514} } @article{kunkel_karl_easterling_redmond_young_yin_hennon_2013, title={Probable maximum precipitation and climate change}, volume={40}, ISSN={["1944-8007"]}, DOI={10.1002/grl.50334}, abstractNote={Probable maximum precipitation (PMP) is the greatest accumulation of precipitation for a given duration meteorologically possible for an area. Climate change effects on PMP are analyzed, in particular, maximization of moisture and persistent upward motion, using both climate model simulations and conceptual models of relevant meteorological systems. Climate model simulations indicate a substantial future increase in mean and maximum water vapor concentrations. For the RCP8.5 scenario, the changes in maximum values for the continental United States are approximately 20%–30% by 2071–2100. The magnitudes of the maximum water vapor changes follow temperature changes with an approximate Clausius‐Clapeyron relationship. Model‐simulated changes in maximum vertical and horizontal winds are too small to offset water vapor changes. Thus, our conclusion is that the most scientifically sound projection is that PMP values will increase in the future due to higher levels of atmospheric moisture content and consequent higher levels of moisture transport into storms.}, number={7}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Kunkel, Kenneth E. and Karl, Thomas R. and Easterling, David R. and Redmond, Kelly and Young, John and Yin, Xungang and Hennon, Paula}, year={2013}, month={Apr} } @article{liang_xu_gao_reddy_kunkel_schmoldt_samel_2012, title={A Distributed Cotton Growth Model Developed from GOSSYM and Its Parameter Determination}, volume={104}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2011.0250}, abstractNote={Prediction of cotton (Gossypium hirsutum L.) production under a changing climate requires a coupled modeling system that represents climate–cotton interactions. The existing cotton growth model GOSSYM has drawbacks that prohibit its effective coupling with climate models. We developed a geographically distributed cotton growth model from the original GOSSYM and optimized it for coupling with the regional Climate–Weather Research Forecasting model (CWRF). This included software redesign, physics improvement, and parameter specification for consistent coupling of CWRF and GOSSYM. Through incorporation of the best available physical representations and observational estimates, the long list of inputs in the original GOSSYM was reduced to two parameters, the initial NO3 amount in the top 2 m of soil and the ratio of irrigated water amount to potential evapotranspiration. The geographic distributions of these two parameters are determined by optimization that minimizes model errors in simulating cotton yields. The result shows that the redeveloped GOSSYM realistically reproduces the geographic distribution of mean cotton yields in 30‐km grids, within ±10% of observations across most of the U.S. Cotton Belt, whereas the original GOSSYM overestimated yields by 27 to 135% at the state level and 92% overall. Both models produced interannual yield variability with comparable magnitude; however, the temporal correspondence between modeled and observed interannual anomalies was much more realistic in the redeveloped than the original GOSSYM because significant (P = 0.05) correlations were identified in 87 and 40% of harvest grids, respectively. The redeveloped GOSSYM provides a starting point for additional improvements and applications of the coupled CWRF–GOSSYM system to study climate–cotton interactions.}, number={3}, journal={AGRONOMY JOURNAL}, author={Liang, Xin-Zhong and Xu, Min and Gao, Wei and Reddy, K. Raja and Kunkel, Kenneth and Schmoldt, Daniel L. and Samel, Arthur N.}, year={2012}, pages={661–674} } @article{kunkel_easterling_kristvich_gleason_stoecker_smith_2012, title={Meteorological Causes of the Secular Variations in Observed Extreme Precipitation Events for the Conterminous United States}, volume={13}, ISSN={["1525-755X"]}, DOI={10.1175/jhm-d-11-0108.1}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF HYDROMETEOROLOGY}, author={Kunkel, Kenneth E. and Easterling, David R. and Kristvich, David A. R. and Gleason, Byron and Stoecker, Leslie and Smith, Rebecca}, year={2012}, month={Jun}, pages={1131–1141} } @article{liang_xu_gao_reddy_kunkel_schmoldt_samel_2012, title={Physical Modeling of US Cotton Yields and Climate Stresses during 1979 to 2005}, volume={104}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2011.0251}, abstractNote={Climate variability and changes affect crop yields by causing climatic stresses during various stages of the plant life cycle. A crop growth model must be able to capture the observed relationships between crop yields and climate stresses before its credible use as a prediction tool. This study evaluated the ability of the geographically distributed cotton growth model redeveloped from GOSSYM in simulating U.S. cotton (Gossypium hirsutum L.) yields and their responses to climate stresses during 1979 to 2005. Driven by realistic climate conditions, the model reproduced long‐term mean cotton yields within ±10% of observations at the 30‐km model resolution across virtually the entire U.S. Cotton Belt and correctly captured the critical dependence of their geographic distributions on regional climate characteristics. Significant correlations between simulated and observed interannual variations were found across 87% of the total harvest grids. The model also faithfully represented the predictive role of July to August air temperature and August to September soil temperature anomalies on interannual cotton yield changes on unirrigated lands, with a similar but weaker predictive signal for irrigated lands as observed. The modeled cotton yields exhibited large, positive correlations with July to August leaf area index. These results indicate the model's ability to depict the regional impact of climate stresses on cotton yields and suggest the potential predictive value of satellite retrievals. They also provide a baseline reference for further model improvements and applications in the future study of climate–cotton interactions.}, number={3}, journal={AGRONOMY JOURNAL}, author={Liang, Xin-Zhong and Xu, Min and Gao, Wei and Reddy, K. Raja and Kunkel, Kenneth and Schmoldt, Daniel L. and Samel, Arthur N.}, year={2012}, pages={675–683} } @article{liang_xu_yuan_ling_choi_zhang_chen_liu_su_qiao_et al._2012, title={REGIONAL CLIMATE-WEATHER RESEARCH AND FORECASTING MODEL}, volume={93}, ISSN={["1520-0477"]}, DOI={10.1175/bams-d-11-00180.1}, abstractNote={The CWRF is developed as a climate extension of the Weather Research and Forecasting model (WRF) by incorporating numerous improvements in the representation of physical processes and integration of external (top, surface, lateral) forcings that are crucial to climate scales, including interactions between land, atmosphere, and ocean; convection and microphysics; and cloud, aerosol, and radiation; and system consistency throughout all process modules. This extension inherits all WRF functionalities for numerical weather prediction while enhancing the capability for climate modeling. As such, CWRF can be applied seamlessly to weather forecast and climate prediction. The CWRF is built with a comprehensive ensemble of alternative parameterization schemes for each of the key physical processes, including surface (land, ocean), planetary boundary layer, cumulus (deep, shallow), microphysics, cloud, aerosol, and radiation, and their interactions. This facilitates the use of an optimized physics ensemble approach to improve weather or climate prediction along with a reliable uncertainty estimate. The CWRF also emphasizes the societal service capability to provide impactrelevant information by coupling with detailed models of terrestrial hydrology, coastal ocean, crop growth, air quality, and a recently expanded interactive water quality and ecosystem model.}, number={9}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Liang, Xin-Zhong and Xu, Min and Yuan, Xing and Ling, Tiejun and Choi, Hyun I. and Zhang, Feng and Chen, Ligang and Liu, Shuyan and Su, Shenjian and Qiao, Fengxue and et al.}, year={2012}, month={Sep}, pages={1363–1387} } @article{kunkel_easterling_kristovich_gleason_stoecker_smith_2010, title={Recent increases in U.S. heavy precipitation associated with tropical cyclones}, volume={37}, ISSN={["0094-8276"]}, DOI={10.1029/2010gl045164}, abstractNote={Precipitation time series for 935 long‐term U.S. climate stations were analyzed to identify daily extreme events associated with tropical cyclones (TCs). Extremes were defined as daily amounts exceeding a threshold for a 1 in 5‐yr occurrence. TCs account for 30% or more of all such extreme events at a number of stations and about 6% of the national annual total. During 1994–2008, the number of TC‐associated events was more than double the long‐term average while the total annual national number of events was about 25% above the long‐term (1895–2008) average. Despite the limited spatial area and portion of the annual cycle affected by TCs, the anomalous number of events associated with TCs accounted for over one‐third of the overall national anomaly for 1994–2008. While there has been a recent increase in the number of landfalling U.S. hurricances, the increase in TC‐associated heavy events is much higher than would be expected from the pre‐1994 association between the two.}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Kunkel, Kenneth E. and Easterling, David R. and Kristovich, David A. R. and Gleason, Byron and Stoecker, Leslie and Smith, Rebecca}, year={2010}, month={Dec} } @article{angel_kunkel_2010, title={The response of Great Lakes water levels to future climate scenarios with an emphasis on Lake Michigan-Huron}, volume={36}, ISSN={0380-1330}, url={http://dx.doi.org/10.1016/j.jglr.2009.09.006}, DOI={10.1016/j.jglr.2009.09.006}, abstractNote={Future climate change and its impact on Lake Michigan is an important issue for water supply planning in Illinois. To estimate possible future levels of the Great Lakes due to climate change, the output of 565 model runs from 23 Global Climate Models were applied to a lake-level model developed by the Great Lakes Environmental Research Laboratory (GLERL). In this study, three future emission scenarios were considered: the B1, A1B, and A2 emission scenarios representing relatively low, moderate, and high emissions, respectively. The results showed that the A2 emission scenario yielded the largest changes in lake levels of the three emission scenarios. Of the three periods examined, lake levels in 2080–2094 exhibited the largest changes. The response of Lake Superior was the smallest of the Great Lakes, while lakes Michigan-Huron, Erie, and Ontario were similar in their response over time and between emission scenarios. For Lake Michigan-Huron, the median changes in lake levels at 2080–2094 were − 0.25, − 0.28, and − 0.41 m for the B1, A1B, and A2 emission scenarios, respectively. However, the range in lake levels was considerable. The wide range of results is due to the differences in emission scenarios and the uncertainty in the model simulations. Selecting model simulations based on their historical performance does little to reduce the uncertainty. The wide range of lake-level changes found here make it difficult to envision the level of impacts that change in future lake levels would cause.}, journal={Journal of Great Lakes Research}, publisher={Elsevier BV}, author={Angel, James R. and Kunkel, Kenneth E.}, year={2010}, month={Jan}, pages={51–58} } @article{kunkel_ensor_palecki_easterling_robinson_hubbard_redmond_2009, title={A new look at lake-effect snowfall trends in the Laurentian Great Lakes using a temporally homogeneous data set}, volume={35}, ISSN={0380-1330}, url={http://dx.doi.org/10.1016/j.jglr.2008.11.003}, DOI={10.1016/j.jglr.2008.11.003}, abstractNote={Snowfall data are subject to quality issues that affect their usefulness for detection of climate trends. A new analysis of lake-effect snowfall trends utilizes a restricted set of stations identified as suitable for trends analysis based on a careful quality assessment of long-term observation stations in the lake-effect snowbelts of the Laurentian Great Lakes. An upward trend in snowfall was found in two (Superior and Michigan) of the four snowbelt areas. The trends for Lakes Erie and Ontario depended on the period of analysis. Although these results are qualitatively similar to outcomes of other recent studies, the magnitude of the upward trend is about half as large as trends in previous findings. The upward trend in snowfall was accompanied by an upward trend in liquid water equivalent for Superior and Michigan, while no trend was observed for Erie and Ontario. Air temperature has also trended upward for Superior and Michigan, suggesting that warmer surface waters and less ice cover are contributing to the upward snowfall trends by enhancing lake heat and moisture fluxes during cold air outbreaks. However, a more comprehensive study is needed to definitely determine cause and effect. Overall, this study finds that trends in lake-effect snowfall are not as large as was believed based on prior research.}, number={1}, journal={Journal of Great Lakes Research}, publisher={Elsevier BV}, author={Kunkel, Kenneth E. and Ensor, Leslie and Palecki, Michael and Easterling, David and Robinson, David and Hubbard, Kenneth G. and Redmond, Kelly}, year={2009}, month={Mar}, pages={23–29} } @article{pryor_howe_kunkel_2009, title={How spatially coherent and statistically robust are temporal changes in extreme precipitation in the contiguous USA?}, volume={29}, ISSN={0899-8418 1097-0088}, url={http://dx.doi.org/10.1002/joc.1696}, DOI={10.1002/joc.1696}, abstractNote={Abstract}, number={1}, journal={International Journal of Climatology}, publisher={Wiley}, author={Pryor, S. C. and Howe, J. A. and Kunkel, K. E.}, year={2009}, month={Jan}, pages={31–45} } @article{huang_lin_tao_choi_patten_kunkel_xu_zhu_liang_williams_et al._2008, title={Impacts of long-range transport of global pollutants and precursor gases on U.S. air quality under future climatic conditions}, volume={113}, ISSN={0148-0227}, url={http://dx.doi.org/10.1029/2007JD009469}, DOI={10.1029/2007JD009469}, abstractNote={The U.S. air quality is impacted by emissions both within and outside the United States. The latter impact is manifested as long‐range transport (LRT) of pollutants across the U.S. borders, which can be simulated by lateral boundary conditions (LBC) into a regional modeling system. This system consists of a regional air quality model (RAQM) that integrates local‐regional source emissions and chemical processes with remote forcing from the LBC predicted by a nesting global chemical transport model (model for ozone and related chemical tracers (MOZART)). The present‐day simulations revealed important LRT effects, varying among the five major regions with ozone problems, i.e., northeast United States, midwest United States, Texas, California, and southeast United States. To determine the responses of the LRT impacts to projected global climate and emissions changes, the MOZART and RAQM simulations were repeated for future periods (2048–2052 and 2095–2099) under two emissions scenarios (IPCC A1Fi and B1). The future U.S. air quality projected by the MOZART is less sensitive to the emissions scenarios than that simulated by the RAQM with or without incorporating the LRT effects via the LBC from the MOZART. The result of RAQM with the LRT effects showed that the southeast United States has the largest sensitivity of surface ozone mixing ratio to the emissions changes in the 2095–2099 climate (−24% to +25%) followed by the northeast and midwest United States. The net increase due to the LRT effects in 2095–2099 ranges from +4% to +13% in daily mean surface ozone mixing ratio and +4% to +11% in mean daily maximum 8‐h average ozone mixing ratios. Correspondingly, the LRT effects in 2095–2099 cause total column O3 mixing ratio increases, ranging from +7% to +16%, and also 2 to 3 more days with the surface ozone exceeding the national standard. The results indicate that future U.S. air quality changes will be substantially affected by global emissions.}, number={D19}, journal={Journal of Geophysical Research}, publisher={American Geophysical Union (AGU)}, author={Huang, Ho-Chun and Lin, Jintai and Tao, Zhining and Choi, Hyun and Patten, Kenneth and Kunkel, Kenneth and Xu, Min and Zhu, Jinhong and Liang, Xin-Zhong and Williams, Allen and et al.}, year={2008}, month={Oct} } @article{liang_kunkel_meehl_jones_wang_2008, title={Regional climate models downscaling analysis of general circulation models present climate biases propagation into future change projections}, volume={35}, ISSN={0094-8276}, url={http://dx.doi.org/10.1029/2007GL032849}, DOI={10.1029/2007GL032849}, abstractNote={A suite of eighteen simulations over the U.S. and Mexico, representing combinations of two mesoscale regional climate models (RCMs), two driving global general circulation models (GCMs), and the historical and four future anthropogenic forcings were intercompared. The RCMs' downscaling reduces significantly driving GCMs' present‐climate biases and narrows inter‐model differences in representing climate sensitivity and hence in simulating the present and future climates. Very high spatial pattern correlations of the RCM minus GCM differences in precipitation and surface temperature between the present and future climates indicate that major model present‐climate biases are systematically propagated into future‐climate projections at regional scales. The total impacts of the biases on trend projections also depend strongly on regions and cannot be linearly removed. The result suggests that the nested RCM‐GCM approach that offers skill enhancement in representing the present climate also likely provides higher credibility in downscaling the future climate projection.}, number={8}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Liang, Xin-Zhong and Kunkel, Kenneth E. and Meehl, Gerald A. and Jones, Richard G. and Wang, Julian X. L.}, year={2008}, month={Apr} } @article{kunkel_huang_liang_lin_wuebbles_tao_williams_caughey_zhu_hayhoe_2008, title={Sensitivity of future ozone concentrations in the northeast USA to regional climate change}, volume={13}, ISSN={1381-2386 1573-1596}, url={http://dx.doi.org/10.1007/S11027-007-9137-Y}, DOI={10.1007/S11027-007-9137-Y}, abstractNote={An air quality modeling system was used to simulate the effects on ozone concentration in the northeast USA from climate changes projected through the end of the twenty-first century by the National Center for Atmospheric Research’s (NCAR’s) parallel climate model, a fully coupled general circulation model, under a higher and a lower scenario of future global changes in concentrations of radiatively active constituents. The air quality calculations were done with both a global chemistry-transport model and a regional air quality model focused on the northeast USA. The air quality simulations assumed no changes in regional anthropogenic emissions of the chemical species primarily involved in the chemical reactions of ozone creation and destruction, but only accounted for changes in the climate. Together, these idealized global and regional model simulations provide insights into the contribution of possible future climate changes on ozone. Over the coming century, summer climate is projected to be warmer and less cloudy for the northeast USA. These changes are considerably larger under the higher scenario as compared with the lower. Higher temperatures also increase biogenic emissions. Both mean daily and 8-h maximum ozone increase from the combination of three factors that tend to favor higher concentrations: (1) higher temperatures change the rates of reactions and photolysis rates important to the ozone chemistry; (2) lower cloudiness (higher solar radiation) increases the photolysis reaction rates; and (3) higher biogenic emissions increase the concentration of reactive species. Regional model simulations with two cumulus parameterizations produce ozone concentration changes that differ by approximately 10%, indicating that there is considerable uncertainty in the magnitude of changes due to uncertainties in how physical processes should be parameterized in the models. However, the overall effect of the climate changes simulated by these models – in the absence of reductions in regional anthropogenic emissions – would be to increase ozone concentrations.}, number={5-6}, journal={Mitigation and Adaptation Strategies for Global Change}, publisher={Springer Science and Business Media LLC}, author={Kunkel, K. E. and Huang, H.-C. and Liang, X.-Z. and Lin, J.-T. and Wuebbles, D. and Tao, Z. and Williams, A. and Caughey, M. and Zhu, J. and Hayhoe, K.}, year={2008}, month={Jun}, pages={597–606} } @article{liang_pan_zhu_kunkel_wang_dai_2006, title={Regional climate model downscaling of the U.S. summer climate and future change}, volume={111}, ISSN={0148-0227}, url={http://dx.doi.org/10.1029/2005JD006685}, DOI={10.1029/2005JD006685}, abstractNote={A mesoscale model (MM5)–based regional climate model (CMM5) integration driven by the Parallel Climate Model (PCM), a fully coupled atmosphere‐ocean‐land‐ice general circulation model (GCM), for the present (1986–1995) summer season climate is first compared with observations to study the CMM5's downscaling skill and uncertainty over the United States. The results indicate that the CMM5, with its finer resolution (30 km) and more comprehensive physics, simulates the present U.S. climate more accurately than the driving PCM, especially for precipitation, including summer mean patterns, diurnal cycles, and daily frequency distributions. Hence the CMM5 downscaling provides a credible means to improve GCM climate simulations. A parallel CMM5 integration driven by the PCM future (2041–2050) projection is then analyzed to determine the downscaling impact on regional climate changes. It is shown that the CMM5 generates climate change patterns very different from those predicted by the driving PCM. A key difference is a summer “warming hole” over the central United States in the CMM5 relative to the PCM. This study shows that the CMM5 downscaling can significantly reduce GCM biases in simulating the present climate and that this improvement has important consequences for future projections of regional climate changes. For both the present and future climate simulations, the CMM5 results are sensitive to the cumulus parameterization, with strong regional dependence. The deficiency in representing convection is likely the major reason for the PCM's unrealistic simulation of U.S. precipitation patterns and perhaps also for its large warming in the central United States.}, number={D10}, journal={Journal of Geophysical Research: Atmospheres}, publisher={American Geophysical Union (AGU)}, author={Liang, Xin-Zhong and Pan, Jianping and Zhu, Jinhong and Kunkel, Kenneth E. and Wang, Julian X. L. and Dai, Aiguo}, year={2006}, month={May}, pages={n/a-n/a} } @article{woodhouse_kunkel_easterling_cook_2005, title={The twentieth-century pluvial in the western United States}, volume={32}, ISSN={0094-8276}, url={http://dx.doi.org/10.1029/2005GL022413}, DOI={10.1029/2005GL022413}, abstractNote={Persistent, widespread wet conditions in the western United States in the early twentieth century have been noted in a number of studies. Here, we investigate the character of this pluvial, which covered a roughly 9‐state region and lasted about 13 years. Paleoclimatic data used to evaluate the period in a long‐term context indicate that the twentieth‐century pluvial is an extremely rare event, as previous studies have suggested, even when assessed in the context of a 1186‐year reconstruction of regional drought. An analysis of twentieth‐century climate data, characterizing precipitation seasonality, intensity, and frequency, shows that the pluvial was primarily a result of winter season, heavy to moderately heavy precipitation events, during a handful of extremely wet winters. Temperatures were also anomalously cool. The combination of duration, intensity, and spatial extent make this an unusual event, not only in twentieth century, but in the past 12 centuries.}, number={7}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Woodhouse, Connie A. and Kunkel, Kenneth E. and Easterling, David R. and Cook, Edward R.}, year={2005}, month={Apr}, pages={n/a-n/a} } @article{kunkel_2004, title={Temporal variations in frost-free season in the United States: 1895–2000}, volume={31}, ISSN={0094-8276}, url={http://dx.doi.org/10.1029/2003GL018624}, DOI={10.1029/2003GL018624}, abstractNote={A newly available data set of daily temperature observations was used to study the temporal variability of the frost‐free season, based on an inclusive 0°C threshold, for 1895–2000 in the conterminous United States. A national average time series of the length of the frost‐free season is characterized by 3 distinct regimes. The period prior to 1930 was notable for decreasing frost‐free season length from 1895 to a minimum around 1910, followed by a marked increase in length of about 1 week from 1910 to 1930. During 1930–1980, frost‐free season length was near the period average with relatively little decadal‐scale variability. Since 1980, frost‐free season length has increased by about 1 week. The national average increase in frost‐free season length from the beginning to the end of the 20th Century is about 2 weeks. Frost‐free season length has increased much more in the western U.S. than in the eastern U.S.}, number={3}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Kunkel, Kenneth E.}, year={2004} }