| 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)短时强降水落区随着辐合区的移动呈现自南向北、自东向西的系统性演变。(2)副热带高压外围持续的水汽输送,辐合线的抬升触发,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。 |
| 关键词: 短时强降水;500hPa两高辐合;积云对流系统;低质心;准静止 |
| DOI： |
| 投稿时间：2020-08-03修订日期：2020-12-01 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Analysis of short heavy rain by convergence zone of two high in Yunnan |
| Wang Zhiguo,Mi Ruizhi,MinYing,Hu Juan,Li Huahong,Xu Yingjie |
| (Yunnan Meteorological Observatory) |
| Abstract: |
| Application data of ERA-interim, routine observation,radar and lighting position,physical, 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:(1)The falling area of short heavy rain is from south to north, from east to west with convergence zone moving.(2)The dynamic mechanism of the short heavy rain occurring and developing are sustainable vapor transportation by subtropical high, uplift by convergence line, severe ascending air.(3) Deep wet layer and warm cloud layer are beneficial to improve precipitation efficiency. (4)The frequency of short heavy rain reduce with cloud-top temperature area who is less than -70℃decreased in mesoscale convective cloud cluster.(5)The cumulus convection system moving slowly by the confrontation of two subtropical high is important reason for short heavy rain.(6) This example accompanied by significantly lightning activity, the number of positive flash increasing and negative flash decreasing with the increased of short heavy rain. |
| Key words: short heavy rain; convergence zone by two high at 500hPa; cumulus convection; low centroid; quasi-stationary |
