2022年4月大气环流和天气分析

Analysis of the April 2022 Atmospheric Circulation and Weather

2022年4月北半球极涡呈单极型分布,强度偏弱;中高纬环流呈三波型,我国基本为正距平,副热带高压较常年均偏弱。全国平均气温为12.4℃,较常年同期偏高0.9℃,为1961年以来第五高。全国平均降水量为45.7 mm,较常年同期偏多4.8%,其中西南地区降水较常年显著偏多。月内仅出现1次冷空气过程,全国范围内共发生2次大范围降水过程,部分地区受风雹影响出现灾情。此外,北方地区出现3次沙尘天气过程,河南、陕西、山西、山东等地气象干旱显露并发展。

The main characteristics of the general atmospheric circulation in April 2022 are as follows.There was one polar vortex center in the Northern Hemisphere,weaker than usual.The circulation in middle-high latitudes showed a three-wave pattern,and there was a positive anomaly of the geopotential height over China.The strength of Western Pacific subtropical high was weaker than that in normal years.The monthly mean temperature was 12.4℃,0.9℃higher than normal,becoming the fifth highest in records since 1961.The monthly mean precipitation amount was 45.7 mm,4.8%more than normal,of which the precipitation in the southwest of China was significantly higher than in normal years.Only one cold air process appeared in this month.Large scale of regional rainfall processes occurred twice in China this month,and some regions were attacked by severe thunderstorm and hail disaster.In addition,northern China experienced three sand-dust weather events,and the hint of drought was found in the provinces of Henan,Shaanxi,Shanxi and Shandong,developing.