气象学报2025，Vol.83Issue(2)：270-285,16.DOI:10.11676/qxxb2025.20240023
冬半年影响江苏不同范围寒潮事件的特征及其环流成因
Characteristics of cold surges affecting different areas of Jiangsu province,China in winter and corresponding circulation patterns
摘要
Abstract
Based on daily air temperature observations and the JRA55 reanalysis data at 69 stations in Jiangsu during 1979-2021,spatiotemporal characteristics of cold wave events(CWE)affecting different areas in Jiangsu in winter(November to March)and corresponding circulation patterns are investigated.The results show that the number of regional cold wave events(R-CWE)affecting Jiangsu in winter was obviously more than that of the large-range cold wave events(L-CWE).The areas affected by R-CWE are mainly concentrated in the Huaibei area,and the areas affected by L-CWE are located in the middle part of Huaibei and southern part of Jianghuai.In addition,there are significantly more R-CWE in November,December and March than in January and February,and more L-CWE in November than in other months.The linear increase trend of R-CWE under global warming is more significant than that of L-CWE,especially that the frequency of R-CWE has increased significantly after 2010.The analysis of circulation shows that a pair of large baroclinic troughs and ridges near the middle and high latitudes of Eurasia are dominant at 500 hPa on day-4 of L-CWE,and cold air in the area north of 75°N can continuously flow southward following the northwest path,while the intensity of circulation anomalies corresponding to R-CWE is significantly weaker than that corresponding to L-CWE in the same period,and cold air mainly comes from the area south of 75°N.The degree to which the circulation system near the Ural Mountains intensifies is the key to distinguish the two types of CWE.On day-2,the intensity of the Siberian high during L-CWE can reach 1043 hPa,5 hPa larger than that during R-CWE.On day 0,its southern boundary extends to 31°N,while R-CWE is located near 38°N.Further investigation shows that the maximum instantaneous blocking frequency near the Ural mountains during the occurrence of L-CWE is 46%,and the anomaly of the Siberian high pressure index basically maintains from day-2 to day-1 and reaches a peak of 6.54 hPa on day-1,with an intensity about twice that of R-CWE.In the early stage of L-CWE,there is a Rossby wave train propagating from the middle and high latitudes to the southeast and can reach the southern part of Jiangsu,which is favorable for the occurrence of a more widespread cold wave event in Jiangsu.In contrast,the Rossby wave train during R-CWE starts 1-2 days later and the intensity is weaker.关键词
江苏/寒潮/时空变化特征/环流异常/波作用通量Key words
Jiangsu/Cold wave/Spatiotemporal characteristics/Circulation anomalies/Wave-activity flux分类
天文与地球科学引用本文复制引用
张梦,王艺橙,吴海英,王蓓元..冬半年影响江苏不同范围寒潮事件的特征及其环流成因[J].气象学报,2025,83(2):270-285,16.基金项目
江苏省气象局科研项目(KQ202324). （KQ202324）
