A5009739765- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Climate Change and Geoengineering
- Atmospheric chemistry and aerosols
- Climate change and permafrost
- Climate Change Policy and Economics
- Geology and Paleoclimatology Research
- Ocean Acidification Effects and Responses
- Cryospheric studies and observations
- Geophysics and Gravity Measurements
- Plant Water Relations and Carbon Dynamics
- Arctic and Antarctic ice dynamics
- Geological Studies and Exploration
- Hydrology and Drought Analysis
- Marine and coastal ecosystems
- Geochemistry and Geologic Mapping
- Ecosystem dynamics and resilience
- Ionosphere and magnetosphere dynamics
- Atmospheric aerosols and clouds
- Aerospace Engineering and Energy Systems
- Methane Hydrates and Related Phenomena
Climate and Global Dynamics Laboratory
2016-2025
NSF National Center for Atmospheric Research
2016-2025
U.S. National Science Foundation
2025
Georgia Institute of Technology
2023
Scripps Institution of Oceanography
2023
Stony Brook University
2023
State University of New York
2023
Lawrence Berkeley National Laboratory
2023
University of California, Los Angeles
2023
University of California, San Diego
2023
The 4-H Study of Positive Youth Development (PYD), a longitudinal investigation diverse sample 1,700 fifth graders and 1,117 their parents, tests developmental contextual ideas linking PYD, youth contributions, participation in community development (YD) programs, representing key ecological asset. Using data from Wave 1 the study, structural equation modeling procedures provided evidence for five firstorder latent factors “Five Cs” PYD (competence, confidence, connection, character, caring)...
Abstract The Whole Atmosphere Community Climate Model version 6 (WACCM6) is a major update of the whole atmosphere modeling capability in Earth System (CESM), featuring enhanced physical, chemical and aerosol parameterizations. This work describes WACCM6 some important features model. can reproduce many modes variability trends middle atmosphere, including quasi‐biennial oscillation, stratospheric sudden warmings, evolution Southern Hemisphere springtime ozone depletion over twentieth...
Abstract. While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how variability responds to increasing anthropogenic perturbations. Thus far Earth system modeling efforts have primarily focused projected changes the sensitivity of specific modes variability, such as El Niño–Southern Oscillation. However, our knowledge forced in overall spectrum higher-order statistics is...
Abstract The coupling between the stratosphere and troposphere following two major stratospheric sudden warmings is studied in Canadian Middle Atmosphere Model using a nudging technique by which zonal-mean evolution of reference are artificially induced an ~100-member ensemble spun off from control simulation. Both taken freely running integration model. One event displacement, other split, both followed extended recoveries lower stratosphere. methodology permits statistically robust study...
This paper describes the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project, which promotes use of a unique model dataset, performed with Community Earth System Model, Whole Atmosphere Climate Model as its atmospheric component [CESM1(WACCM)], to investigate global and regional impacts geoengineering. The simulations were designed achieve multiple simultaneous climate goals, by strategically placing sulfur injections at four different locations in stratosphere, unlike many...
Abstract The stratosphere can have a significant impact on winter surface weather subseasonal to seasonal (S2S) timescales. This study evaluates the ability of current operational S2S prediction systems capture two important links between and troposphere: (1) changes in probabilistic skill extratropical by precursors tropics troposphere (2) predictability extratropics after stratospheric weak strong vortex events. Probabilistic exists for events when including tropospheric over North Pacific...
Application of random sampling techniques to composite differences between 18 El Niño and 14 La Niña events observed since 1920 reveals considerable uncertainty in both the pattern amplitude Northern Hemisphere extratropical winter sea level pressure (SLP) response ENSO. While SLP responses over North Pacific America are robust variability, their magnitudes can vary by a factor 2; other regions, such as Arctic, Atlantic, Europe less patterns, amplitudes, statistical significance. The...
Previous studies have extensively investigated the impact of Arctic sea ice anomalies on midlatitude circulation and associated surface climate in winter. However, there is an ongoing scientific debate regarding whether how retreat results observed cold anomaly over adjacent continents. We present a robust "cold Siberia" pattern winter following loss Barents-Kara seas late autumn advanced atmospheric general model, with well-resolved stratosphere. Additional targeted experiments reveal that...
Abstract Mediterranean-type climates are defined by temperate, wet winters, and hot or warm dry summers exist at the western edges of five continents in locations determined geography winter storm tracks summer subtropical anticyclones. The climatology, variability, long-term changes precipitation climates, mechanisms for model-projected near-term future change, analyzed. Despite commonalities terms location context planetary-scale dynamics, causes variability distinct across regions....
Abstract Geoengineering methods could potentially offset aspects of greenhouse gas‐driven climate change. However, before embarking on any such strategy, a comprehensive understanding its impacts must be obtained. Here, 20‐member ensemble simulations with the Community Earth System Model Whole Atmosphere Climate as atmospheric component is used to investigate projected hydroclimate changes that occur when warming, under high emissions scenario, stratospheric aerosol geoengineering. Notable...
Abstract The quasi‐biennial oscillation (QBO) of the zonal mean wind is primary mode variability in tropical lower stratosphere. QBO characterized by alternating easterly westerly shear layers that descend down from ∼10 to 100 hPa. also seen stratospheric temperature, water vapor, and ozone affects tropospheric through various teleconnections. We examine here progress simulating Coupled Model Intercomparison Project (CMIP) models, more specifically CMIP3, CMIP5, CMIP6 models. show number...
Abstract The stratosphere has been identified as an important source of predictability for a range processes on subseasonal to seasonal (S2S) time scales. Knowledge about S2S within the is however still limited. This study evaluates what extent in extratropical exists hindcasts operational prediction systems database. found exhibit extended compared troposphere. Prediction with higher stratospheric skill tend also analysis includes assessment events, including early and midwinter sudden...
Abstract The evolving roles of anthropogenic aerosols (AER) and greenhouse gases (GHG) in driving large-scale patterns precipitation SST trends during 1920–2080 are studied using a new set “all-but-one-forcing” initial-condition large ensembles (LEs) with the Community Earth System Model version 1 (CESM1), which complement original “all-forcing” CESM1 LE (ALL). number ensemble members (15–20) each LEs enables regional impacts AER GHG to be isolated from noise model’s internal variability....
Arid and semi-arid regions of the world are particularly vulnerable to greenhouse gas–driven hydroclimate change. Climate models our primary tool for projecting future that society in these must adapt to, but here, we present a concerning discrepancy between observed model-based historical trends. Over arid/semi-arid world, predominant signal all model simulations is an increase atmospheric water vapor, on average, over last four decades, association with increased vapor–holding capacity...
Abstract A simplified general circulation model has been used to investigate the chain of causality whereby changes in tropospheric and temperature are produced response stratospheric heating perturbations. Spinup ensemble experiments have performed examine evolution such The primary aim these is possible mechanisms a changing solar activity over 11-yr cycle could be equatorial lower stratosphere. This study therefore focuses on perturbation which largest tropics. For comparison, also...
Abstract Zonal-mean or basin-mean analyses often conclude that the midlatitude circulation will undergo a poleward shift with global warming. In this study, models from phase 5 of Coupled Model Intercomparison Project are used to provide detailed examination change as function longitude and season. The two-dimensional vertically integrated momentum budget is identify dominant terms maintain anomalous surface wind stress, thereby allowing distinction between features maintained by...
Abstract The hydrological cycle in the Mediterranean region, as well its change over coming decades, is investigated using Interim European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim) and phase 5 of Coupled Model Intercomparison Project (CMIP5) historical simulations projections decades. land regions have positive precipitation minus evaporation, P − E, winter negative E summer. According to ERA-Interim, sustained by transient eddy moisture convergence opposed mean...
Abstract The mechanisms of model-projected atmospheric moisture budget change across North America are examined in simulations conducted with 22 models from phase 5 the Coupled Model Intercomparison Project. Modern-day model budgets validated against European Centre for Medium-Range Weather Forecasts Interim Re-Analysis. In winter half year transient eddies converge continent while mean flow wets west central California northward and dries southwest. summer there is widespread divergence...
Abstract Previous studies have documented a poleward shift in the subsiding branches of Earth’s Hadley circulation since 1979 but disagreed on causes these observed changes and ability global climate models to capture them. This synthesis paper reexamines number contradictory claims past literature finds that tropical expansion indicated by modern reanalyses is within bounds models’ historical simulations for period 1979–2005. Earlier conclusions were underestimating trends relied defining...
Abstract The Community Earth System Model 2 (CESM2) is the latest developed by National Center for Atmospheric Research in collaboration with university community and significantly advanced most components compared to its predecessor (CESM1). Here, CESM2's representation of large‐scale atmospheric circulation variability assessed. Further context providedthrough comparison CESM1 large ensemble other models from Coupled Intercomparison Project (CMIP5 CMIP6). This includes an assessment jet...
Geoengineering with stratospheric sulfate aerosols can, to some extent, be designed achieve different climate objectives. Here we use the state-of-the-art Community Earth System Model, version 1, Whole Atmosphere Climate Model as its atmospheric component (CESM1(WACCM)), compare surface and effects of two geoengineering strategies. In one, SO2 is injected into tropical lower stratosphere at equator keep global mean temperature nearly constant under an RCP8.5 scenario, has been commonly...