青藏高原夏季中尺度强对流系统的时空分布

The Spatial and Temporal Distributions of Severe Mesoscale Convective Systems over Tibetan Plateau in Summer

摘要: 利用1994年6～8月GMS-4红外展宽数字资料，统计和分析了青藏高原上293个中尺度强对流系统（s-MCS）的活动。结果表明，它们在高原上活动频繁，并且其生命史、水平尺度及强度具有较典型的中-β尺度系统特征；它们的形成和发展主要是由于地形热力效应；它们的移动方向与300～200 hPa间的平均气流方向大体一致，并且极少移出高原。

Abstract: By using GMS-4 hourly IR stretched digital data from June through August 1991, all 293 severe Mesoscale Convective Systems (s-MCSs) Over Tibetan Plateau were investigated and analysed. The results show that those s-MCSs had larger frequency and more typical features of Meso-β scale system in its life cycle, size and intensity; their initiation and development was mainly derived from the thermotopographic effect; their movement basically consorted with the mean flow between 300 and 200 hPa, and few of them moved away from Tibetan Plateau.