Analysis of Equation for Convective Vorticity Vector during a Torrential Rainfall Process in Meiyu Season of 2011

Abstract

Using NCEP FNL analysis data,black body temperature from FY-2E satellite,conventional and auto-metrological stations' observational precipitation data,and simulation output from high-resolution mesoscale model WRF V3. 3 to analyze a precipitation process in Jiang-Huai valley in June 2011. Analysis results show that the simulation results are in good agreement with the observations when comparing the precipitation betw een simulations and observations and reproduce the precipitation process well. This precipitation process was controlled and influenced by the surface low and Meiyu front systems. Period from 14 to 15 June is the mature phase of whole precipitation process,and the most significant character of this period is that many mesoscale convective systems move and develop along the Meiyu front. To investigate how MCS impacts on Meiyu front and torrential rainfall,convective vorticity vector and its vertical component tendency equation were employed to analyze. The result shows that local variation for the vertical component was influenced by the diabatic term,and the relationships among diabatic heating,secondary circulation and Meiyu frontogenesis imply a CISK-like response betw een MCS and Meiyu frontogenesis. So as a good atmospheric variable,the convective vorticity vector,especially,the vertical component can be used to diagnose and reveal the relationship betw een MCS associated with diabatic heating and Meiyu frontogenesis.