摘要
2021年4月中高纬大气环流为三波型,极涡呈单极偏心型分布,强度偏强,西太平洋副热带高压强度较常年偏弱,南支槽较常年偏强。4月主要天气气候特点是全国平均气温为11.1℃,较常年同期偏高0.1℃;全国平均降水量为42.5 mm,较常年同期(45.1 mm)偏少5.8%,其中青海平均月降水量为历史同期第一多。月内,我国遭受四次冷空气过程影响;西南和华南东部气象干旱持续或发展;北方地区出现两次沙尘天气过程;多地遭受风雹袭击,部分地区受灾较重。
The main characteristics of the general atmospheric circulation in April 2021 are as follows.The 500 hPa geopotential height presented a three wave pattern in the high latitude of Northern Hemisphere.There was one polar vortex center in the Northern Hemisphere,stronger than usual.The strength of Western Pacific subtropical high was weaker than that in normal years,but the south branch trough was stronger than usual.The monthly mean temperature was 11.1℃,0.1℃higher than normal.The monthly mean precipitation over China was 42.5 mm,which is 5.8%less than normal.However,the mean precipitation in Qinghai Province this month was recorded the most for the same period of history.Four nationwide strong cold air processes happened this month.The drought conditions in Southwest China and eastern part of South China persisted or worsened.Two sand dust events occurred across the northern part of China.Several provinces were attacked by severe thunder storms and hail,and some areas were hit harder.
作者
麦子
张涛
盛杰
MAI Zi;ZHANG Tao;SHENG Jie(National Meteorological Centre,Beijing 100081)
出处
《气象》
CSCD
北大核心
2021年第7期893-900,共8页
Meteorological Monthly
基金
国家重点研发计划(2017YFC1502003)资助。
关键词
大气环流
冷空气
暴雨
强对流
沙尘
atmospheric circulation
cold air
heavy rain
severe convection
sand and dust
