库尔勒市大降水天气的环流背景及其中尺度触发机制分析

利用库尔勒市2005-2013年暖季逐小时降水量资料分析了当地大降水天气的发生的时间、强度特征,从天气预报的角度对大降水天气环流形势进行了分型、找出了产生大降水的中尺度触发抬升机制,建立了大降水天气的三种概念模型。研究得到库尔勒大降水影响系统包括低槽或涡东移型、南北低槽汇合型、锋区南压型以及脊前短波槽或西北气流型四类,降水触发机制分为冷锋触发类、干线触发类以及混合触发类三种。结合大降水发生前的影响系统、发生时抬升触发机制和雷暴降水天气形成的动力、水汽、不稳定条件以及大降水落区的显著特征的总结分析,归纳出包括了锋区急流类大降、低涡气旋类大降水以及低槽切变辐合线类大降水三种不同的库尔勒大降水天气概念模型。

Analyze of circulation background of heavy rain process and mesoscale triggermechanism in Korla

Based on the hourly data of precipitation in warm season of Korla. The climate character of occurrence and strength as well as circulation situations resulting in heavy rain events were also analyzed from aspect of weather forecast. The mesoscale of lifting trigger mechanism and the three conceptual model of heavy rain were found. The heavy rain were classified to four influence system, including east moving trough of low pressure or vortex, the confluent trough from southern and northern, frontal mass south pressing, the short wave trough or southeasterly flow before ridge. There were three trigger mechanisms which were cold-front , dew-point front, the blending type including cold-front and dew-point front. By summary analysis of characteristics of dynamic,water vapor and instability conditions as well as heavy rain distribution. Concluding three conceptual models which were jet stream front and low vortex cyclone as well as low trough with shear line or convergence line.