THE NUMERICAL SIMULATION STUDY OF CONVECTIVESTRATIFORM MIXED CLOUD, PART(Ⅰ)─THE MODEL AND PARAMETERIZATION OFMICROPHYSICAL PROCESSES

A 2-D slab-symmetric model of convective-stratiform mixed cloud is developed by superimposing convective cloud-size field on the convergence field, in order to simulate and study the mixed cloud consisting of stratiform cloud and convective clouds. A deep convective. anelastic and conservative system of equations with basic variables (V, B, π) is solved by a new method to calculate dynamic field. The water substance in the cloud is dividded into 6 categorys and the microphysical processes are described in spectram with two variable parameters and more reasonable particle number/size distributions. To comparing with measured redar echo intensity and structure. the model may calculate echo intensity of the model cloud observed by radar.