Schematic diagram of Cumulus convection parameterization 


    Brief introduction to Cumulus convection parameterization

  "The horizontal scale and time scale of deep cumulus clouds are two or more orders smaller than those of synoptic weather systems, while their vertical scales are similar. Hence, an individual cloud might not be expected to have much influence on a large-scale system; however clouds are frequently organized in groups with a scale comparable to that of synoptic systems. Consequently, the cumulative effect of a large number of individual clouds may have significant effect on the large-scale system through the transfer of heat, moisture, and momentum." - Haltiner and Williams(1980)

  Cumulus convection scheme in CESAGCM is basically based on Arakawa and Schubert (1974)'s massflux method but is modified by Numaguti et al. (1995) as a simplified form. This scheme calculates the tendencies of temperature and humidity (the effect of cumulus momentum transport is now in verification) by the result of interaction between grid scale circulation and sub-grid scale cloud ensemble. Cloud liquid water and cumulus cloud fraction is also determined for radiative processes.

    Diagram of Details (Click to see how the equations are calcuated in codes!)