青藏高原地区深对流系统特征分析

基于2014—2018年3—9月GPM(Global Precipitation Measurement)的数据,对青藏高原地区的深对流系统的时空分布及降水特征进行研究,结果表明:青藏高原主体地区(25°～40°N,70°～105°E)的深对流系统主要集中分布在中部、东部和南部地区,对流强度与东亚季风区其他区域相比较小,而对流强度相对较大的系统则大多分布在高原东部地区。深对流系统主要发生在夏季,7、8月份频数达到峰值且对流较强,且主要活动区域有先向南、向西扩展再东退的特点。深对流活动主要从午后开始发展,大体呈单峰分布。高原深对流系统产生的降水强度较弱,主要集中在5mm/h以下,其产生的降水主要来源于回波顶高度较低、面积较小的弱对流活动。

Characteristics of Deep Convective System over Tibetan Plateau

Based on the GPM (Global Precipitation Measurement mission) data from March to September in 2014-2018, the temporal and spatial distribution of the deep convective system and precipitation characteristics of the Tibetan Plateau region are studied. The results show that the deep convective systems in the main area of the Tibetan Plateau (25°-40°N, 70°-105°E) were mainly concentrated in the central, eastern and southern regions. The convective intensity was relatively small compared with other regions of the East Asian monsoon region, while the systems with relatively large convective intensity were mostly distributed in the eastern region of the Plateau. The deep convection systems mainly occurred in summer. In July and August, the frequency peaks and the convection were strong. The main activity area had the characteristics of extending southward, westward, and then retreating eastward. The deep convective activities mainly developed in the afternoon and showed a unimodal distribution. The precipitation intensity produced by the deep convective system of the plateau was relatively weak, mainly concentrated below 5 mm/h, and the precipitation produced by it also mainly was induced by weak convective activities with a low echo top height and small area.