2022年12月大气环流和天气分析

Analysis of the December 2022 Atmospheric Circulation and Weather

2022年12月大气环流的主要特征是:北半球极涡呈偶极型分布,东亚大槽偏强,环流形势有利于冷空气活动;南支槽偏弱,西太平洋副热带高压偏东,不利于降水天气的发展。12月,全国平均降水量为7.5 mm,较常年同期(11.9 mm)偏少37%;全国平均气温为-4.2℃,较常年同期(-3.0℃)偏低1.2℃。月内出现了4次冷空气过程,1次沙尘天气过程。冷空气活动频繁,全国大部地区大气扩散条件较好;11—13日沙尘天气过程强度强,发生时间偏晚。

The main characteristics of the general atmospheric circulation in December 2022 are as follow.There were two polar vortex centers in the Northern Hemisphere.The East Asian trough was stronger than in the same period of normal years,which was conducive to the outbreak of cold airs.The southern branch trough was weaker and the western Pacific subtropical high was located more eastward than the normal,which was not good for the formation of precipitation.The monthly mean precipitation over China was 7.5 mm,which is less than normal(11.9 mm)by 37%.The monthly average temperature was-4.2℃,1.2℃lower than the normal(3.0℃).During this month,cold airs were very active and there occurred four nationwide cold wave processes,so the atmospheric diffusion conditions were good in most regions of China.The sand-dust storm process from 11 to 13 December was stronger and occurred later than in the December of normal years.