2014年2月大气环流和天气分析

Analysis of Atmosphere Circulation and Weather in February 2014

2014年2月大气环流的主要特征是极涡偏强且呈偶极型分布,中高纬环流呈4波型,西太平洋副热带高压偏弱,南支槽位置偏西。2月全国平均气温为-2.3℃,较常年同期偏低0.6℃;全国平均降水量17.5 mm,与常年同期(17.4 mm)持平。月内我国有一次全国性寒潮天气过程;北方有明显雨(雪)天气,冬麦区旱情缓解;南方雨雪过程较多且范围较大,多地出现阶段性低温雨雪天气和冻害;中东部出现3次大范围的雾或霾天气过程。

The main characteristics of the general atmospheric circulation in February 2014 are as follows:There were two polar vortex centres in the Northern Hemisphere and both of them are stronger than nor-mal.The atmospheric circulation represents a four-wave pattern over the middle-high latitudes.The northwestern Pacific subtropical high is weaker than normal and the south branch trough is more to the west than normal.The monthly mean temperature is -2.3℃,0.6℃ lower than normal.The monthly mean precipitation amount is 17.5 mm,which is similar to the normal value.During this month,there is one nationwide cold wave process.Obvious rain and snow weathers are seen in the north of China,relie-ving the drought situation in the winter wheat area.The snow and rain processes are more in the south of China with a large range impacted,which makes many places suffer from cryogenic rain/snow weather and cold damages.Besides,three fog and haze processes appear in the middle and eastern part of China.