2023年8月大气环流和天气分析

Analysis of the August 2023 Atmospheric Circulation and Weather

2023年8月大气环流的主要特征是:北半球极涡强度略偏强,500 hPa上亚洲中高纬地区环流形势为“两槽一脊”,影响我国东北、华北地区的高空槽偏强,西太平洋副热带高压西段脊线的平均位置较历史同期偏南。8月,全国平均气温为21.9℃,较常年同期(21.1℃)偏高0.8℃,全国平均降水量为110.9 mm,较常年同期(107.1 mm)偏多3.5%。月内,高温日数较常年同期偏多,区域高温过程持续影响我国,西北、东北等地气象干旱持续发展;我国出现6次暴雨过程。8月共有6个台风在南海和西北太平洋活动,生成个数较常年偏多,登陆个数较常年偏少。强对流天气多发,局地受灾严重,江苏盐城大丰区出现龙卷风。

The main characteristics of the general atmospheric circulation in August 2023 are as follows.The intensity of the polar vortex was slightly stronger in the Northern Hemisphere.The circulation over the mid-to-high latitudes of Asia at 500 hPa showed“two troughs”and“one ridge”.The high-altitude trough affecting the northeastern and northern of China is stronger.The mean location of the ridge line in the western part of the Western Pacific subtropical high was more southward compared to that in normal years.In August,the monthly average temperature was 21.9℃,0.8℃higher than in the same period of normal years(21.1℃).The monthly average precipitation was 110.9 mm,which is 3.5%higher than normal(107.1 mm).During this month,the high temperature days were more than normal,with regional high temperature processes appearing successively in China.Meteorological drought continued to in the northwest and northeast of China.Six torrential rain events were reported in China.In August,six typhoons were active in the South China Sea and the Western North Pacific.The generation number of tropical cyclones was higher than that in the previous years,but the number of landfall typhoons was lower than usual.Severe convective weather was frequent and local disasters were severe.In addition,one tornado hit the Dafeng District,Yancheng of Jiangsu Province.