利用NCEP/NCAR再分析资料对2002年6月14—15日的暴雨过程进行了诊断分析,并利用中尺度模式MM5对暴雨过程进行云迹风资料的同化模拟。诊断分析表明:高空急流的动量下传、高低空急流的适宜配置所产生的动力场的耦合作用,为此次大范围暴雨的发生、发展提供了动力条件;此次暴雨过程充足稳定的水汽主要源自印度洋。对同化效果进行检验说明:两个时次的云迹风资料同化模拟与一个时次的云迹风资料同化模拟相比,前者更进一步地改善风场、温度场和高度场,使得物理量场和降水场的预报更加接近实况。
A diagnostic analysis of a rainstorm process during June 14-15,2005 is performed based on the NCEP/NCAR reanalysis data, and the simulation of the process is conducted using the meso-scale MM5 model with the assimilation of cloud-derived wind data. The results show that the strengthening of a high-level jet stream and its momentum downward-spreading impelled the maintenance of the low-level jet, and the coupling of the high- and low-level jets provided a proper dynamical condition for the occurrence and development of the torrential rain process. The abundant and stable vapor supply to the rainstorm process mainly originated from the Indian Ocean. The effects of cloud-derived wind assimila- tion were examined in sensitive experiments;the wind, temperature, geopotential height fields are more significantly improved in the experiment with the cloud-derived wind assimilation of two time levels than those in that with one time level assimilation, thus the predicted physical variable and rainfall fields in the former are closer to the observed fields than in the latter.