A5085295028- Climate variability and models
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Medical Imaging Techniques and Applications
- Arctic and Antarctic ice dynamics
- Hydrology and Watershed Management Studies
- Scientific Computing and Data Management
- Soil and Water Nutrient Dynamics
- demographic modeling and climate adaptation
- Air Quality Monitoring and Forecasting
- Marine and coastal ecosystems
- Simulation Techniques and Applications
- Water Quality and Pollution Assessment
- Geophysics and Gravity Measurements
- Geological and Geophysical Studies
- Groundwater flow and contamination studies
- Distributed and Parallel Computing Systems
- Fluid Dynamics and Turbulent Flows
- Water Quality Monitoring and Analysis
- Groundwater and Isotope Geochemistry
NSF National Center for Atmospheric Research
2016-2025
NSF NCAR Climate and Global Dynamics Laboratory
2011-2022
University Corporation for Atmospheric Research
2015
University of Reading
1999-2009
Joint Research Centre
2005
Institute of Hydrology of the Slovak Academy of Sciences
1988
UK Centre for Ecology & Hydrology
1986
Princeton University
1985
Association for Asian Studies
1985
University of Michigan
1985
The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to climate community. This paper describes developments all CCSM components, documents fully coupled preindustrial control runs compared previous version, CCSM3. Using standard atmosphere land resolution 1° results in sea surface temperature biases major upwelling regions being comparable 1.4°-resolution Two changes deep convection scheme component result CCSM4 producing El Niño–Southern...
The Community Earth System Model (CESM) is a flexible and extensible community tool used to investigate diverse set of system interactions across multiple time space scales. This global coupled model significantly extends its predecessor, the Climate Model, by incorporating new simulation capabilities. These comprise ability simulate biogeochemical cycles, including those carbon nitrogen, variety atmospheric chemistry options, Greenland Ice Sheet, an atmosphere that lower thermosphere. other...
An overview of the Community Earth System Model Version 2 (CESM2) is provided, including a discussion challenges encountered during its development and how they were addressed. In addition, an evaluation pair CESM2 long preindustrial control historical ensemble simulations presented. These performed using nominal 1° horizontal resolution configuration coupled model with both "low-top" (40 km, limited chemistry) "high-top" (130 comprehensive versions atmospheric component. contains many...
Abstract While internal climate variability is known to affect projections, its influence often underappreciated and confused with model error. Why? In general, modeling centers contribute a small number of realizations international assessments [e.g., phase 5 the Coupled Model Intercomparison Project (CMIP5)]. As result, error are difficult, at times impossible, disentangle. response, Community Earth System (CESM) community designed CESM Large Ensemble (CESM-LE) explicit goal enabling...
A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), atmospheric component of Earth System 1 (CESM1). MAM is capable simulating size distribution and both internal external mixing between components, treating numerous complicated processes physical, chemical optical properties in a physically-based manner. Two versions were developed: more complete with seven lognormal modes (MAM7), three (MAM3) purpose long-term (decades to centuries)...
Abstract The Community Atmosphere Model, version 4 (CAM4), was released as part of the Climate System (CCSM4). finite volume (FV) dynamical core is now default because its superior transport and conservation properties. Deep convection parameterization changes include a dilute plume calculation convective available potential energy (CAPE) introduction momentum (CMT). An additional cloud fraction performed following macrophysical state updates to provide improved thermodynamic consistency. A...
This work documents the first version of U.S. Department Energy (DOE) new Exascale Earth System Model (E3SMv1). We focus on standard resolution fully coupled physical model designed to address DOE mission-relevant water cycle questions. Its components include atmosphere and land (110-km grid spacing), ocean sea ice (60 km in midlatitudes 30 at equator poles), river transport (55 km) models. base configuration will also serve as a foundation for additional configurations exploring higher...
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 The NCAR Community Climate System Model, version 3 (CCSM3) exhibits persistent errors in its simulation of the El Niño–Southern Oscillation (ENSO) mode coupled variability. amplitude oscillation is too strong, dominant 2-yr period regular, and width sea surface temperature response Pacific narrow, with positive anomalies extending far into western Pacific. Two changes parameterization deep convection result a significant improvement to many aspects ENSO simulation. inclusion...
Abstract The Community Earth System Model Version 2 (CESM2) has an equilibrium climate sensitivity (ECS) of 5.3 K. ECS is emergent property both feedbacks and aerosol forcing. increase in over the previous version (CESM1) result cloud feedbacks. Interim versions CESM2 had a land model that damped ECS. Part change results from evolving configuration to reproduce long‐term trend global regional surface temperature twentieth century response forcings. Changes made reduce aerosols also impacted...
The Maritime Continent, with its complex system of islands and shallow seas, presents a major challenge to models, which tend systematically underestimate the precipitation in this region. Experiments climate version Met Office model (HadAM3) show that even threefold increase horizontal resolution there is no improvement dry bias. It argued diurnal cycle over circulation patterns generated by land–sea contrasts are crucial for energy hydrological cycles Continent determining mean climate....
Abstract The ability of eight climate models to simulate the Madden–Julian oscillation (MJO) is examined using diagnostics developed by U.S. Climate Variability and Predictability (CLIVAR) MJO Working Group. Although signal has been extracted throughout annual cycle, this study focuses on boreal winter (November–April) behavior. Initially, maps mean state variance equatorial space–time spectra 850-hPa zonal wind precipitation are compared with observations. Models best represent...
Abstract The Energy Exascale Earth System Model Atmosphere version 1, the atmospheric component of Department Energy's is described. model began as a fork well‐known Community Model, but it has evolved in new ways, and coding, performance, resolution, physical processes (primarily cloud aerosols formulations), testing development procedures now differ significantly. Vertical resolution was increased (from 30 to 72 layers), top extended 60 km (~0.1 hPa). A simple ozone photochemistry predicts...
Abstract We present an unprecedented set of high‐resolution climate simulations, consisting a 500‐year pre‐industrial control simulation and 250‐year historical future from 1850 to 2100. A configuration the Community Earth System Model version 1.3 (CESM1.3) is used for simulations with nominal horizontal resolution 0.25° atmosphere land models 0.1° ocean sea‐ice models. At these resolutions, model permits tropical cyclones mesoscale eddies, allowing interactions between synoptic phenomena...
Abstract This study provides an overview of the coupled high‐resolution Version 1 Energy Exascale Earth System Model (E3SMv1) and documents characteristics a 50‐year‐long control simulation with time‐invariant 1950 forcings following HighResMIP protocol. In terms global root‐mean‐squared error metrics, this is generally superior to results from low‐resolution configuration E3SMv1 (due resolution, tuning changes, possibly initialization procedure) compares favorably models in CMIP5 ensemble....
Abstract Extended, high-resolution (0.23° latitude × 0.31° longitude) simulations with Community Atmosphere Model versions 4 and 5 (CAM4 CAM5) are examined compared results from climate conducted at a more typical resolution of 0.9° 1.25° longitude. Overall, the simulated experiments is not dramatically better than that their low-resolution counterparts. Improvements appear primarily where topographic effects may be playing role, including substantially improved summertime Indian monsoon...
Abstract This study provides comprehensive insight into the notable differences in clouds and precipitation simulated by Energy Exascale Earth System Model Atmosphere version 0 1 (EAMv1). Several sensitivity experiments are conducted to isolate impact of changes model physics, resolution, parameter choices on these differences. The overall improvement EAMv1 is primarily attributed introduction a simplified third‐order turbulence parameterization Cloud Layers Unified By Binormals (along with...
Abstract The Community Earth System Model version 2 (CESM2) simulates a high equilibrium climate sensitivity (ECS > 5°C) and Last Glacial Maximum (LGM) that is substantially colder than proxy temperatures. In this study, we examine the role of cloud parameterizations in simulating LGM cooling CESM2. Through substituting different versions schemes atmosphere model, attribute excessive to new CESM2 microphysics ice nucleation. Further exploration suggests removing an inappropriate limiter...
A new configuration of the Community Earth System Model (CESM)/Community Atmosphere with full chemistry (CAM-chem) supporting capability horizontal mesh refinement through use spectral element (SE) dynamical core is developed and called CESM/CAM-chem-SE. Horizontal in CESM/CAM-chem-SE unique novel that pollutants such as ozone are accurately represented at human exposure relevant scales while also directly including global feedbacks. down to ∼14 km over conterminous US (CONUS) beginning...
Abstract To assist model intercomparison and development of a set eight numerical experiments is proposed as test‐bed for the interaction dynamics physical parameterizations in atmospheric GCMs. The framework that an aqua‐planet prescribed sea‐surface temperatures (SSTs) are highly idealized. Copyright © 2001 Royal Meteorological Society.
[1] Lateral mixing parameters in buoyancy-driven deep convection schemes are among the most sensitive and important unknowns atmosphere models. Unfortunately, there is not a true optimum value for plume rate, but rather dilemma or tradeoff: Excessive dilution of updrafts leads to unstable stratification bias mean state, while inadequate allows occur too easily, causing poor space time distributions variability. In this too-small parameter space, compromises made based on competing metrics...
Abstract It is the purpose of this paper to provide a comprehensive documentation new NCAR (National Center for Atmospheric Research) version spectral element (SE) dynamical core as part Community Earth System Model (CESM2.0) release. This differs from previous releases SE in several ways. Most notably hybrid sigma vertical coordinate based on dry air mass, condensates are dynamically active thermodynamic and momentum equations (also referred condensate loading), continuous motion conserve...