2016年8月大气环流和天气分析

Analysis of the August 2016 Atmospheric Circulation and Weather

2016年8月环流特征如下:北半球极涡呈单极型分布,强度偏强;亚洲大陆中、高纬为两槽一脊型;西北太平洋副热带高压位置明显偏东偏北、强度偏弱,大陆高压偏强。8月全国平均降水93.9 mm,较常年同期(105.7 mm)偏少11.2%;全国平均气温22℃,较常年同期(20.8℃)偏高1.2℃,为1961年以来历史同期最高,全国大部地区气温偏高。月内共出现了6次主要的区域性强降水过程,其中4次是由热带气旋或热带辐合带活动引起。8月共有8个热带气旋(风力8级以上)在西北太平洋和南海海域活动,其中1604号台风妮妲和1608号台风电母登陆华南沿海。月内,我国中东部地区出现大范围持续高温天气,东北地区西部和内蒙古东部气象干旱持续。

The main characteristics of the general circulation in August 2016 are as follows. The polar vortex of the Northern Hemisphere presents a single pattern. In the mid high latitudes of Asia, the circulation presents a two trough and one ridge pattern. The subtropical high lies eastward and northward obviously, and its intensity in northwestern Pacific Ocean is weaker than its average state during the corresponding period of normal years, and the high pressure on land is stronger than the average. Meanwhile, the monthly mean precipitation is 93.9 mm, which is 11.2% less than its normal value （105.7 mm）. The monthly mean temperature is 22℃, 1.2℃ higher than its climatological mean （20.8℃）, which is the highest historical record since 1961. Six regional torrential rainfall events happened in August, and four of them were caused by tropical cyclones or tropical disturbances. In August, eight tropical cyclones were active over the northwestern Pacific Ocean and the South China Sea, and Typhoons Nida （1604） and Dianmu （1608） made landfall along the coastal areas over southern China. Long lasting and large scale high temperature occurred all over the central and eastern part of China. Continuous drought happened over the western part of Northeast and eastern Inner Mongolia of China.