2014年4月大气环流和天气分析

Analysis of the April 2014 Atmospheric Circulation and Weather

2014年4月大气环流特征为,北半球极涡呈单极型分布,中心位于喀拉海北端附近;亚洲大陆东部高压脊强度偏强,导致4月我国气温较常年同期(11.0℃)偏高1.1℃,为1961年同期以来第五高值。东亚大槽强度和位置、南支系统和西北太平洋副热带高压接近常年平均状况。4月全国平均降水量为43.7 mm,比常年同期略偏少。月内,江南南部和华南等地出现短时强降水、雷雨大风等强对流天气;北方地区出现多次沙尘天气过程;此外,部分站次出现极端高温、极端降温事件。

The characteristics of general circulation of atmosphere in April 2014 are as follows.There is one single center of the Northern Hemisphere polar vortex which is located near as the northern part of Kara Sea.The Asia ridge is stronger,because of which,the mean temperature of April in China is 1 1℃,1 .1℃higher than the normal,and is recorded as the fifth highest one from 1961.The position and strength of East Asia trough,south branch,and subtropical high of Northwest Pacific all are neutral compared to the normal condition.In April,the monthly mean precipitation over China is 43 .7 mm,slightly less than the normal.In addition,strong convective weathers like short-time severe precipitation,thunders-storm high winds,etc.occur in the southern part of Jiangnan Region and South China.Moreover,there are several sand and dust events in north of China,and extreme high temperature and sharp drop in temperature are observed by some stations.