edu.ucar.gdex::d583117 eng; USA utf-8 dataset NSF NCAR Geoscience Data Exchange datahelp@ucar.edu https://gdex.ucar.edu NSF NCAR Geoscience Data Exchange The Geoscience Data Exchange (GDEX), managed by the Computational and Information Systems Laboratory (CISL) at NSF NCAR, contains a large collection of meteorological, atmospheric composition, and oceanographic observations, and operational and reanalysis model outputs, integrated with NSF NCAR High Performance Compute services to support atmospheric and geosciences research. download pointOfContact 2026-04-20T17:49:18Z ISO 19115 Geographic Information - Metadata ISO19115:2003/Cor 1 2006 https://doi.org/10.5065/8406-p773 Datasets used in Bacmeister et al, JAMES (2020). " CO2 increase experiments ..." d583117 2020-09-28 publication Bacmeister, Julio T. author Hannay, Cecile author NSF National Center for Atmospheric Research publisher Datasets used in the creation of original figures of Bacmeister et al. JAMES (2020). CO2 increase experiments using the Community Earth System Model (CESM): Relationship to climate sensitivity and comparison of CESM1 to CESM2. We examine the response of the Community Earth System Model versions 1 and 2 (CESM1 and CESM2) to abrupt quadrupling of atmospheric CO2 concentrations (4xCO2) and to 1% annually increasing CO2 concentrations (1% CO2). Different estimates of equilibrium climate sensitivity (ECS) for CESM1 and CESM2 are presented. All estimates show that the sensitivity of CESM2 has increased by 1.5K or more over that of CESM1. At the same time the transient climate response (TCR) of CESM1 and CESM2 derived from 1% CO2 experiments has not changed significantly - 2.1K in CESM1 and 2.0K in CESM2. Increased initial forcing as well as stronger shortwave radiation feedbacks are responsible for the increase in ECS seen in CESM2. A decomposition of regional radiation feedbacks and their contribution to global feedbacks shows that the Southern Ocean plays a key role in the overall behavior of 4xCO2 experiments, accounting for about 50% of the total shortwave feedback in both CESM1 and CESM2. The Southern Ocean is also responsible for around half of the increase in shortwave feedback between CESM1 and CESM2, with a comparable contribution arising over tropical ocean. Experiments using a thermodynamic slab-ocean model (SOM) yield estimates of ECS that are in remarkable agreement with those from fully-coupled earth system model (ESM) experiments for the same level of CO2 increase. Finally, we show that the similarity of TCR in CESM1 and CESM2 masks significant regional differences in warming that occur in the 1% CO2 experiments for each model. completed datahelp@ucar.edu pointOfContact notPlanned dataset https://gdex.ucar.edu/images/ds_logos/default_200_200.png Logo thumbnail from URL png NetCDF dataset Resource Type 2021-03-30 revision 4.4 DataCite Metadata Working Group orginator resourceTypeGeneral CESM > NCAR Community Earth System Model U.S. National Aeronautics and Space Administration Global Change Master Directory GCMD 2026-04-15 revision 23.7 NASA Global Change Master Directory orginator Valids List: Platforms EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC CHEMISTRY > CARBON AND HYDROCARBON COMPOUNDS > ATMOSPHERIC CARBON DIOXIDE U.S. National Aeronautics and Space Administration Global Change Master Directory GCMD 2026-04-15 revision 23.7 NASA Global Change Master Directory orginator Valids List: Science and Services Keywords Creative Commons Attribution 4.0 International License None eng utf-8 climatologyMeteorologyAtmosphere NSF NCAR Geoscience Data Exchange datahelp@ucar.edu https://gdex.ucar.edu distributor 628114.951 https://gdex.ucar.edu/datasets/d583117/ https Dataset Description Related Link information https://gdex.ucar.edu/datasets/d583117/dataaccess/ https Data Access Related Link download none asNeeded