新疆一次深秋局地短时大暴雨的成因分析  

Analysis of a Brief Torrential Rain Event in Autumn in Xinjiang

作　　者：杨霞 李云[2] 赵逸舟[3] 于永波[3] 黄艳 

机构地区：[1]新疆气象台,乌鲁木齐830002 [2]中国气象局国家气象卫星中心,北京100081 [3]乌鲁木齐市气象局,乌鲁木齐830002 [4]喀什地区气象局,喀什843305

出　　处：《高原气象》2014年第1期162-170,共9页Plateau Meteorology

基　　金：国家科技支撑计划项目(2012BAC23B01);中国沙漠气象科学研究基金(sqj2013006);新疆气象局科技研究项目(200702)

摘　　要：利用自动站逐时观测资料、FY-2D高分辨率卫星云图资料及NCEP/NCAR每6 h一次的再分析资料,采用25点平滑算子的尺度分离法,分析了2011年10月21日新疆博尔塔拉蒙古自治州(下称博州)的一次短历时大暴雨过程的中尺度特征及其发生、发展机理。结果表明,博州地区前期温度异常偏高,为深秋时节出现强对流天气蓄积了较好的热力条件。强降水过程中博州地区上空的中尺度垂直环流圈为大暴雨的产生提供了有利的动力条件。中尺度气旋的位置与TBB分布有较好的对应关系,其中心与TBB低值中心的移动方向一致。大气层结不稳定对中尺度对流云团的发生、发展具有促进作用,低层水汽的强烈辐合为对流云团和降水的形成提供了必要条件。地形在本次强降水过程中具有重要作用,地形的抬升和收缩作用使得辐合上升运动加强;地面中尺度辐合线和中尺度低压对本次大暴雨过程具有触发作用。Based on the data of hourly precipitation cal Satellite from China Meteorological Agency and in Xinjiang and the data of FY --2D Stationary Meteorologi- the reanalysis dataset from the NCEP/NCAR reanalysis pro- ject, the mesoscale characteristic and the mechanism of a brief torrential rain event in Xinjiang are analyzed by the 25-point smooth filter methods. The results show that the temperature in Bozhou in the earlier stage is slightly higher than normal, which provide the thermodynamic conditions for the brief torrential rain event in late fall. There is a mesoscale vertical circulation cycle in Bozhou, which provides the favorable dynamic condition for the torrential rain. The position and the moving direction of mesoscale cyclone and TBB are all the same. Unsteady stratified atmosphere has great impact on the maintaining and development of the mesoscale convective cloud mass over Bozhou. Continuous moisture convergence and potential instable energy transportation in the lower layers provide enough water and energy for the lasting heavy precipitation over the rainstorm area. The effect of terrain to the heavy rain event is very important. The surface mesoscale convergence line and mesoscale depres- sion may be the trigger system.

关 键 词：短历时大暴雨 中小尺度系统 中尺度滤波 触发机制 

分 类 号：P445[天文地球—大气科学及气象学]