Comparison study of two turbulence parameterization in meso-scale numerical weather forecasting

The non-local turbulence parameterization, i. e., transilient theory was used in the host model MM4 to simulate the turbulent activities of the atmosphere. The control models are the standard MM4 using the Blackadar high resolution boundary scheme, the bulk boundary scheme, the KUO cumulus parameterization scheme and explicit clouds. Results of comparison indicate that although some oversea study of the transilient theory succeeded in a degree, if the transilient theory is to be used in model MM4, substantial improvement of the expression of the vertical mixing potential is necessary, or an empirical filter should be applied to ameliorate the result of forecasting. Although the location of rainfall is the same as the host model, the expression used in many researches had the tendency of over-mixing, leading to the decreasing of rainfall.EI03405-4133