IMPROVEMENTS OF AN ICE-PHASE MICROPHYSICS PARAMETERIZATION FOR USE INNUMERICAL SIMULATIONS OF TROPICAL CONVECTION

It is important to properly simulate the extent and ice water content of tropical anvil clouds in numerical models that explicitly include c loud formation because of the significant effects that these clouds ha ve on the radiation budget. For this reason, a commonly used bulk ice- phase microphysics parameterization was modified to more realistically simulate some of the microphysical processes that occur in tropical a nvil clouds. Cloud ice growth by the Bergeron process and the associat ed formation of snow were revised. The characteristics of graupel were also modified in accord with a previous study. Numerical simulations of a tropical squall line demonstrate that the amount of cloud ice and the extent of anvil clouds are increased to more realistic values by the first two changes.