Climate Processes in CMIP5: An investigation of the connections between convection, clouds and climate sensitivity in a Global Climate Model
For the global warming experiments, all models explored here produce an increase in precipitation efficiency to warming. The intermodel variation in response of cloud condensate, low and middle cloud fraction, and total cloud radiative forcing are well explained by model variations in response of precipitation efficiency or cloud detrainment efficiency. A substantial fraction of the increase in precipitation efficiency to warming is due to its convective component which depends on the parameterization of cumulus mixing and convective microphysics processes. The differing response in convective precipitation efficiency to warming explains the increased cloud feedback and climate sensitivity in recently developed Geophysical Fluid Dynamics Laboratory GCMs.