江苏省快速(24 h)寒潮事件特征分析及环流分型研究

Characteristics of rapid (24 h) cold wave events and circulation patterns in Jiangsu Province

  • 摘要: 利用江苏省基本气象站1951—2023年逐日最低气温资料和NCEP/NCAR再分析资料,对江苏省快速(24 h)寒潮事件(简称快速寒潮事件,下同)基本特征和主要环流型进行分型分析. 研究发现:(1)快速寒潮事件次数呈现由北向南递减特征,空间差异明显. 江苏西北部和东南部寒潮强度大,西南部寒潮强度略小. 快速寒潮事件随着影响范围增大而出现次数减少,寒潮事件都是区域性,以一般性强度为主;(2)快速寒潮事件主要集中在冬季,1月最多,降温极值发生在12月,而平均强度3月最强,1月最弱. 快速寒潮事件次数和强度在20世纪70年代之前相对较多、较强,之后呈现波动性减少和减弱的趋势,21世纪初之后有增多、增强的趋势;(3)快速寒潮事件主要分为北低南高型和西低东高型;(4)北低南高环流型的冷空气强度更强,大部分西低东高环流型的冷空气相对较弱,但极少数发生的西低东高环流型也能造成较强的快速寒潮事件.

     

    Abstract: Based on the daily minimum temperature data and NCEP/NCAR reanalysis data from the conventional meteorological stations in Jiangsu Province from 1951 to 2023, the basic characteristics and main circulation types of rapid (24 h) cold wave events (referred to as fast cold wave events, the same below) in Jiangsu Province are analyzed. The results show that: (1) The frequency of rapid cold wave events decreases from north to south, and the spatial difference is obvious. The intensity of cold wave events is high in the northwest and southeast of Jiangsu province, and slightly smaller in the southwest of Jiangsu. The number of cold wave events decreases with the increase of the affected area, and the cold wave events are all regional, mainly of general intensity; (2) The events are mainly concentrated in winter, with the highest in January, the extreme value of cooling occurres in December, and the average intensity is the strongest in March and the weakest in January. The frequency and intensity of rapid cold wave events are relatively more and stronger before 1970s, and then show a trend of decreasing and weakening volatility, and then increasing and strengthening after the beginning of the 21st century; (3) The rapid cold wave events are mainly divided into the north-low-south-high type and the west-low-east-high type; (4) The intensity of cold air in the north-low-south-high circulation type is stronger, and most of the cold air in the west-low and east-high circulation type is relatively weaker, but a very small number of west-low-east-high circulation types can also cause strong rapid cold wave events.

     

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