Schematics of shallow convection parameterization

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  Introduction of shallow convection parameterization

 When convection on a global scale is discussed it is often deep convection in the tropics that receives the greatest attention. Much recent work on the development of improved representations of convection for use in GCMs has concentrated upon this area. However, shallow convection also plays an important role in global circulation, and global simulations are sensitive to the manner in which it is parametrized. Although several mass-flux parametrizations represent shallow convection (Tiedtke 1989; Gregory and Rowntree 1990), comparatively less attention has been given to considering the effects of such processes.

   Most GCMs consider sub-grid moist process only as generatingprecipitation at the process of cumulus convection. But this makes systematic bias of performance of thermodynamic structure at boundary layer and intensity of equatorial heat source. From this discovery improvement of parameterization is needed to represent vertical mass exchange at non-precipitating cumulus.