2014年3月大气环流和天气分析

Analysis of the March 2014 Atmospheric Circulation and Weather

2014年3月大气环流特征为:北半球极涡呈偏心型,主体位于北美北部,同时在新地岛和鄂霍次克海附近分别有2个低涡中心,较常年平均状况,前者异常偏强10 dagpm左右,后者位置偏南,亚洲大陆高压脊异常偏强6 dagpm左右,范围异常偏大,导致3月我国气温较常年同期(4.1℃)异常偏高1.2℃,为1961年以来第六高值。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。3月我国平均降水量为29.1 mm,接近常年平均值(29.5 mm)。月内,南方多阴雨天气,北方地区出现沙尘天气过程,中东部出现雾或霾天气过程,多省出现雷雨大风、冰雹等强对流天气。

The characteristics of general circulation of atmosphere in March 2014 are following.The polar vortex in the Northern Hemisphere is eccentric type with the main body located in the northern part of North America and there are two other vortex centers positioned near Novaya Zemlya and Okhotsk Sea re-spectively.Compared to the normal mean condition,the former one is stronger about -10 dagpm in the geopotential height anomaly and the later one is nearly neutral lying further south.The Asia ridge is stron-ger about 6 dagpm in geopotential height anomaly and its area is larger,because of which the mean temper-ature of March is 1.2℃higher than the normal temperature 4.1℃,recorded as the 6th highest since 1961. The position and strength of East Asia trough,south branch,and subtropical high of the Northwest Pacif-ic all are neutral compared to the normal conditions.The mean precipitation in March is 29.1 mm,ap-proaching to the normal average 29.5 mm.In March,there are more cloudy and rainy days in the south of China,but dust weather in the north,fog and haze processes in the central and eastern part,and severe convective weathers in many provinces.