skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The Community Climate System Model Version 4

Abstract

The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to the climate community. This paper describes developments to all the CCSM components, and documents fully coupled pre-industrial control runs compared to the previous version, CCSM3. Using the standard atmosphere and land resolution of 1{sup o} results in the sea surface temperature biases in the major upwelling regions being comparable to the 1.4{sup o} resolution CCSM3. Two changes to the deep convection scheme in the atmosphere component result in the CCSM4 producing El Nino/Southern Oscillation variability with a much more realistic frequency distribution than the CCSM3, although the amplitude is too large compared to observations. They also improve the representation of the Madden-Julian Oscillation, and the frequency distribution of tropical precipitation. A new overflow parameterization in the ocean component leads to an improved simulation of the deep ocean density structure, especially in the North Atlantic. Changes to the CCSM4 land component lead to a much improved annual cycle of water storage, especially in the tropics. The CCSM4 sea ice component uses much more realistic albedos than the CCSM3, and the Arctic sea ice concentration is improved in the CCSM4. An ensemble of 20th century simulationsmore » runs produce an excellent match to the observed September Arctic sea ice extent from 1979 to 2005. The CCSM4 ensemble mean increase in globally-averaged surface temperature between 1850 and 2005 is larger than the observed increase by about 0.4 C. This is consistent with the fact that the CCSM4 does not include a representation of the indirect effects of aerosols, although other factors may come into play. The CCSM4 still has significant biases, such as the mean precipitation distribution in the tropical Pacific Ocean, too much low cloud in the Arctic, and the latitudinal distributions of short-wave and long-wave cloud forcings.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1029045
Report Number(s):
PNNL-SA-74968
Journal ID: ISSN 0894-8755; JLCLEL; TRN: US201122%%676
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Climate
Additional Journal Information:
Journal Volume: 24; Journal Issue: 19; Journal ID: ISSN 0894-8755
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; AEROSOLS; AMPLITUDES; CLIMATES; CLOUDS; CONVECTION; DISTRIBUTION; OSCILLATIONS; PACIFIC OCEAN; PRECIPITATION; RESOLUTION; SEAS; SIMULATION; STORAGE; UPWELLING; WATER

Citation Formats

Gent, Peter R, Danabasoglu, Gokhan, Donner, Leo J, Holland, Marika M, Hunke, Elizabeth C, Jayne, Steve R, Lawrence, David M, Neale, Richard, Rasch, Philip J, Vertenstein, Mariana, Worley, Patrick, Yang, Zong-Liang, and Zhang, Minghua. The Community Climate System Model Version 4. United States: N. p., 2011. Web. doi:10.1175/2011JCLI4083.1.
Gent, Peter R, Danabasoglu, Gokhan, Donner, Leo J, Holland, Marika M, Hunke, Elizabeth C, Jayne, Steve R, Lawrence, David M, Neale, Richard, Rasch, Philip J, Vertenstein, Mariana, Worley, Patrick, Yang, Zong-Liang, & Zhang, Minghua. The Community Climate System Model Version 4. United States. doi:10.1175/2011JCLI4083.1.
Gent, Peter R, Danabasoglu, Gokhan, Donner, Leo J, Holland, Marika M, Hunke, Elizabeth C, Jayne, Steve R, Lawrence, David M, Neale, Richard, Rasch, Philip J, Vertenstein, Mariana, Worley, Patrick, Yang, Zong-Liang, and Zhang, Minghua. Sat . "The Community Climate System Model Version 4". United States. doi:10.1175/2011JCLI4083.1.
@article{osti_1029045,
title = {The Community Climate System Model Version 4},
author = {Gent, Peter R and Danabasoglu, Gokhan and Donner, Leo J and Holland, Marika M and Hunke, Elizabeth C and Jayne, Steve R and Lawrence, David M and Neale, Richard and Rasch, Philip J and Vertenstein, Mariana and Worley, Patrick and Yang, Zong-Liang and Zhang, Minghua},
abstractNote = {The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to the climate community. This paper describes developments to all the CCSM components, and documents fully coupled pre-industrial control runs compared to the previous version, CCSM3. Using the standard atmosphere and land resolution of 1{sup o} results in the sea surface temperature biases in the major upwelling regions being comparable to the 1.4{sup o} resolution CCSM3. Two changes to the deep convection scheme in the atmosphere component result in the CCSM4 producing El Nino/Southern Oscillation variability with a much more realistic frequency distribution than the CCSM3, although the amplitude is too large compared to observations. They also improve the representation of the Madden-Julian Oscillation, and the frequency distribution of tropical precipitation. A new overflow parameterization in the ocean component leads to an improved simulation of the deep ocean density structure, especially in the North Atlantic. Changes to the CCSM4 land component lead to a much improved annual cycle of water storage, especially in the tropics. The CCSM4 sea ice component uses much more realistic albedos than the CCSM3, and the Arctic sea ice concentration is improved in the CCSM4. An ensemble of 20th century simulations runs produce an excellent match to the observed September Arctic sea ice extent from 1979 to 2005. The CCSM4 ensemble mean increase in globally-averaged surface temperature between 1850 and 2005 is larger than the observed increase by about 0.4 C. This is consistent with the fact that the CCSM4 does not include a representation of the indirect effects of aerosols, although other factors may come into play. The CCSM4 still has significant biases, such as the mean precipitation distribution in the tropical Pacific Ocean, too much low cloud in the Arctic, and the latitudinal distributions of short-wave and long-wave cloud forcings.},
doi = {10.1175/2011JCLI4083.1},
journal = {Journal of Climate},
issn = {0894-8755},
number = 19,
volume = 24,
place = {United States},
year = {2011},
month = {10}
}