The Mean Climate of the Community Atmosphere Model (CAM4) in Forced SST and Fully Coupled Experiments

Abstract The Community Atmosphere Model, version 4 (CAM4), was released as part of the Community Climate System Model, version 4 (CCSM4). The finite volume (FV) dynamical core is now the default because of its superior transport and conservation properties. Deep convection parameterization changes include a dilute plume calculation of convective available potential energy (CAPE) and the introduction of convective momentum transport (CMT). An additional cloud fraction calculation is now performed following macrophysical state updates to provide improved thermodynamic consistency. A freeze-drying modification is further made to the cloud fraction calculation in very dry environments (e.g., the Arctic), where…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy
• NC
  National Center for Atmospheric Research
• OO
  Office of Science
• BA
  Biological and Environmental Research