2021年7月大气环流和天气分析

Analysis of the July 2021 Atmospheric Circulation and Weather

2021年7月主要环流特征为北半球极涡呈偶极型分布且较常年同期偏强,西北太平洋高压较常年偏西偏北,强度偏强。7月,全国平均气温为23.1℃,较常年同期(21.8℃)偏高1.3℃;全国平均降水量为124.4 mm,较常年同期(120.6 mm)偏多3.2%。月内共有7次强降水过程,多站降水突破历史极值,河南出现破纪录极端降水。7月共有3个热带气旋在南海和西北太平洋活动,其中2106号台风烟花与2107号台风查帕卡登陆我国,登陆个数与常年同期持平。华南、江南、新疆及内蒙古西部地区出现大范围持续性高温天气,多个站点日最高气温突破历史极值。

The general atmospheric circulation in July 2021 was mainly characterized by polar vortexes in Arctic Region with two centers stronger than normal,and the western North Pacific subtropical high was located more weastern and northern to the climatological location with stronger intensity.The national averaged monthly mean temperature in China was 23.1℃,1.3℃higher than the climatology(21.8℃).The national averaged monthly precipitation in China was 124.4 mm,3.2%more than the climatology(120.6 mm).There were seven severe rain processes in July 2021,of which the most extreme one occurred in Henan Province,where observed precipitations at many sites broke the historical records.Among the three tropical cyclones active over the South China Sea and western North Pacific,No.2106 Typhoon Yanhua and No.2107 Typhoon Chapaka made landfall in China.The total landing numbers of typhoon were equal to normal.In addition,the long-lasting and wide-spreading high temperature events occurred in South China,south of Yangtze River,Xinjiang,and western part of the Inner Mongolia with daily maximum temperature at many sites breaking the historical records.