Sensitivity to Glacial Forcing in the CCSM4
Findings are introduced from the Community Climate System Model, version 4 (CCSM4), simulation of the Last Glacial Maximum (LGM) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) at the standard 1° resolution, the same resolution as the majority of the CCSM4 CMIP5 long-term simulatio...
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ftosti:oai:osti.gov:1565085 2023-07-30T03:56:34+02:00 Sensitivity to Glacial Forcing in the CCSM4 Brady, Esther C. Otto-Bliesner, Bette L. Kay, Jennifer E. Rosenbloom, Nan 2022-05-26 application/pdf http://www.osti.gov/servlets/purl/1565085 https://www.osti.gov/biblio/1565085 https://doi.org/10.1175/jcli-d-11-00416.1 unknown http://www.osti.gov/servlets/purl/1565085 https://www.osti.gov/biblio/1565085 https://doi.org/10.1175/jcli-d-11-00416.1 doi:10.1175/jcli-d-11-00416.1 54 ENVIRONMENTAL SCIENCES 2022 ftosti https://doi.org/10.1175/jcli-d-11-00416.1 2023-07-11T09:37:06Z Findings are introduced from the Community Climate System Model, version 4 (CCSM4), simulation of the Last Glacial Maximum (LGM) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) at the standard 1° resolution, the same resolution as the majority of the CCSM4 CMIP5 long-term simulations for the historical and future projection scenarios. The forcings and boundary conditions for this simulation follow the protocols of the Paleoclimate Modeling Intercomparison Project, version 3 (PMIP3). Two additional CCSM4 CO 2 sensitivity simulations, in which the concentrations are abruptly changed at the start of the simulation to the low 185 ppm LGM concentrations (LGMCO2) and to a quadrupling of the preindustrial concentration (4×CO 2 ), are also analyzed. For the full LGM simulation, the estimated equilibrium cooling of the global mean annual surface temperature is 5.5°C with an estimated radiative forcing of -6.2 W m -2 . The radiative forcing includes the effects of the reduced LGM greenhouse gases, ice sheets, continental distribution with sea level lowered by approximately 120 m from the present, and orbital parameters, but not changes to atmospheric aerosols or vegetation biogeography. The LGM simulation has an equilibrium climate sensitivity (ECS) of 3.1(±0.3)°C, comparable to the CCSM4 4×CO 2 result. The LGMCO 2 simulation shows a greater ECS of 4.2°C. Other responses found at the LGM in CCSM4 include a global precipitation rate decrease at a rate of ~2% °C -1 , similar to climate change simulations in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4); a strengthening of the Atlantic meridional overturning circulation (AMOC) with a shoaling of North Atlantic Deep Water and a filling of the deep basin up to sill depth with Antarctic Bottom Water; and an enhanced seasonal cycle accompanied by reduced ENSO variability in the eastern Pacific Ocean’s SSTs. Other/Unknown Material Antarc* Antarctic North Atlantic Deep Water North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic Pacific Journal of Climate 26 6 1901 1925 |
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Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Brady, Esther C. Otto-Bliesner, Bette L. Kay, Jennifer E. Rosenbloom, Nan Sensitivity to Glacial Forcing in the CCSM4 |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Findings are introduced from the Community Climate System Model, version 4 (CCSM4), simulation of the Last Glacial Maximum (LGM) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) at the standard 1° resolution, the same resolution as the majority of the CCSM4 CMIP5 long-term simulations for the historical and future projection scenarios. The forcings and boundary conditions for this simulation follow the protocols of the Paleoclimate Modeling Intercomparison Project, version 3 (PMIP3). Two additional CCSM4 CO 2 sensitivity simulations, in which the concentrations are abruptly changed at the start of the simulation to the low 185 ppm LGM concentrations (LGMCO2) and to a quadrupling of the preindustrial concentration (4×CO 2 ), are also analyzed. For the full LGM simulation, the estimated equilibrium cooling of the global mean annual surface temperature is 5.5°C with an estimated radiative forcing of -6.2 W m -2 . The radiative forcing includes the effects of the reduced LGM greenhouse gases, ice sheets, continental distribution with sea level lowered by approximately 120 m from the present, and orbital parameters, but not changes to atmospheric aerosols or vegetation biogeography. The LGM simulation has an equilibrium climate sensitivity (ECS) of 3.1(±0.3)°C, comparable to the CCSM4 4×CO 2 result. The LGMCO 2 simulation shows a greater ECS of 4.2°C. Other responses found at the LGM in CCSM4 include a global precipitation rate decrease at a rate of ~2% °C -1 , similar to climate change simulations in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4); a strengthening of the Atlantic meridional overturning circulation (AMOC) with a shoaling of North Atlantic Deep Water and a filling of the deep basin up to sill depth with Antarctic Bottom Water; and an enhanced seasonal cycle accompanied by reduced ENSO variability in the eastern Pacific Ocean’s SSTs. |
author |
Brady, Esther C. Otto-Bliesner, Bette L. Kay, Jennifer E. Rosenbloom, Nan |
author_facet |
Brady, Esther C. Otto-Bliesner, Bette L. Kay, Jennifer E. Rosenbloom, Nan |
author_sort |
Brady, Esther C. |
title |
Sensitivity to Glacial Forcing in the CCSM4 |
title_short |
Sensitivity to Glacial Forcing in the CCSM4 |
title_full |
Sensitivity to Glacial Forcing in the CCSM4 |
title_fullStr |
Sensitivity to Glacial Forcing in the CCSM4 |
title_full_unstemmed |
Sensitivity to Glacial Forcing in the CCSM4 |
title_sort |
sensitivity to glacial forcing in the ccsm4 |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1565085 https://www.osti.gov/biblio/1565085 https://doi.org/10.1175/jcli-d-11-00416.1 |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/1565085 https://www.osti.gov/biblio/1565085 https://doi.org/10.1175/jcli-d-11-00416.1 doi:10.1175/jcli-d-11-00416.1 |
op_doi |
https://doi.org/10.1175/jcli-d-11-00416.1 |
container_title |
Journal of Climate |
container_volume |
26 |
container_issue |
6 |
container_start_page |
1901 |
op_container_end_page |
1925 |
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1772813740542001152 |