云南一次两高辐合型短时强降水过程的成因分析  

Analysis of Short Heavy Rain by Convergence Zone of Two High in Yunnan

作　　者：王治国 米瑞芝 闵颖[1] 胡娟[1] 李华宏[1] 许迎杰[1] WANG Zhiguo;MI Ruizhi;MIN Ying;HU Juan;LI Huahong;XU Yingjie(Yunnan Meteorological Observatory,Kunming 650034,China)

机构地区：[1]云南省气象台,云南昆明650034

出　　处：《中低纬山地气象》2021年第3期48-55,共8页Mid-low Latitude Mountain Meteorology

基　　金：中国气象局预报员专项(CMAYBY2019-107):模式产品对云南暖区降水预报性能的评估研究;国家自然科学基金项目(41565004):云南强降水过程背景下短时强降水天气特征分析及机理研究;国家自然科学基金项目(41805037):西行台风影响下云南强降水天气过程的机理研究;云南省科技惠民项目(2016RA096):云南强对流灾害性天气短时临近预警系统研究。

摘　　要：利用ERA-interim再分析资料、常规观测资料、雷达资料以及闪电定位仪资料,对2015年8月云南一次两高辐合形势下短时强降水发生的成因和中尺度特征进行分析。结果表明:①此次短时强降水过程具有分布范围广、降水时段集中、频次大等特点。②副热带高压和孟加拉湾外围持续的水汽输送,地面冷锋的抬升触发,低层辐合、高层辐散且散度辐合中心和上升运动中心叠置,有利于强烈上升运动形成,是短时强降水发生发展和维持的动力机制。③湿层深厚、暖云层厚度大,有利于降水效率的提高。④中尺度对流云团中随着云顶亮温小于-70℃区域面积的减小,短时强降水的频次也明显减少。⑤两高势力相当,形成对峙,导致低质心高效率的积云对流系统移动缓慢,呈准静止状态是短时强降水得以发生的重要原因。⑥此次过程伴有明显的闪电活动,且随着短时强降水站次数的增加,正闪次数明显增加,负闪次数明显减少。Based on the application data of ERA-interim,routine observation,radar and lighting position,a short heavy rain by convergence zone of two high in Yunnan province from 20∶00 BT 25 to 20∶00 BT 26 August 2015 was analyzed.The main results are as follows:①The characteristics of the short heavy rain process were of wide distribution,comparatively concentrative and high frequency.②The dynamic mechanism of the short heavy rain occurring and developing are sustainable vapor transportation by subtropical high,Bengal bay storm,surface cold front,severe ascending air.③Deep wet layer and warm cloud layer are beneficial to improve precipitation efficiency.④The frequency of short heavy rain reduce with cloud-top temperature area who is less than-70℃decreased in mesoscale convective cloud cluster.⑤The cumulus convection system moving slowly by the confrontation of two subtropical high is an important reason for short heavy rain.⑥This example accompanied by significantly lightning activity,the number of positive flash increasing and negative flash decreasing with the increased of short heavy rain.

关 键 词：短时强降水 500 hPa两高辐合 积云对流系统 低质心 准静止 

分 类 号：P458.121[天文地球—大气科学及气象学]