85th AMS Annual Meeting

Wednesday, 12 January 2005: 1:30 PM
An appraisal of coupled climate model simulations: mean state
Peter J. Gleckler, LLNL, Livermore, CA; and K. AcutaRao, C. Covey, C. Doutriaux, M. Fiorino, T. Phillips, K. Sperber, and K. E. Taylor
The climate simulations analyzed in PCMDI's first appraisal of coupled ocean-atmosphere models are drawn from submissions to the second phase of the Coupled Model Intercomparison Project, designated as CMIP2+. In this presentation we focus on the mean state and drift of the simulated atmosphere and ocean in the CMIP2+ control run simulations.

We will examine the overall climate drift in these simulations by looking at global and hemispheric secular trends in surface air temperature, sea surface temperature, total sea ice extent, and ocean basin averaged temperature and salinity as a function of depth. Results suggest that these simulations are relatively drift-free, including those without flux adjustment.

We will summarize some basic features of the simulated climate by analyzing twenty year climatologies of the atmosphere and ocean. We compare the atmosphere from these coupled model runs with atmosphere-only simulations (resulting from Atmospheric Model Intercomparison Project), and demonstrate how the multi-model mean compares statistically better with observations than any individual model. We will compare the ocean basins with observed (Levitus) temperature and salinity, and demonstrate that the Arctic Basin stands out relatively poorly compared to the other major basins.

Acknowledgments. This work was performed under the auspices of the U.S. Department of Energy Office of Science, Climate Change Prediction Program by University of California Lawrence Livermore National Laboratory Under contract No. W-7405-Eng-48.

Supplementary URL: