The main characteristics of the general atmospheric circulation in October 2023 are that the polar vortex was distributed in a multipolar pattern,the mid-and high-latitude regions in Eurasia were mainly controlled by high-pressure ridges,the western Pacific subtropical high was obviously strong,located to more northward,showing a zonal distribution,and there were tropical depressions in eastern Asia.In Oc-tober,the monthly mean temperature was 12.0℃,1.4℃ higher than that of the same period in normal years(10.6 ℃).The monthly average precipitation was 35.4 mm,which was the same as the normal value(35.6 mm).During this month,the autumn rainfall in West China was excessive and more prolonged,bringing torrential rains and floods to some areas.The number of generated typhoons was less than normal but above-normal typhoons made landfall,with heavier impacts to the affected areas.Among them,Ty-phoon Koinu triggered severe precipitation in South China,and Typhoon Samba made landfall in China three times,causing disasters in South China.In addition,there were two cold air processes and one fog-haze weather event during this month.
关键词
大气环流/副热带高压/台风/气温偏高/华西秋雨
Key words
atmospheric circulation/subtropical high/typhoon/above-normal temperature/autumn rain in West China