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

作　　者：张梦 王艺橙 吴海英[3] 王蓓元 ZHANG Meng;WANG Yicheng;WU Haiying;WANG Beiyuan(Huaian Meteorological Bureau,Huaian 223001,China;Huaian Lianshui International Airport Limited Liability Company,Huaian 223432,China;Jiangsu Meteorological Observatory,Nanjing 210041,China)

机构地区：[1]淮安市气象局,淮安223001 [2]淮安涟水国际机场有限责任公司,淮安223432 [3]江苏省气象台,南京210041

出　　处：《气象学报》2025年第2期270-285,共16页Acta Meteorologica Sinica

基　　金：江苏省气象局科研项目(KQ202324)。

摘　　要：利用1979—2021年江苏地区69个站点的逐日气温观测资料和JRA55再分析资料对冬半年(11月—次年3月)影响江苏不同范围寒潮事件(Cold Wave Events,CWE)的时空变化特征及其环流成因进行探究。结果表明:冬半年影响江苏的区域性寒潮事件(Regional Cold Wave Events,R-CWE)发生数量较大范围寒潮事件(Large-range Cold Wave Events,L-CWE)明显偏多,R-CWE影响区域主要集中在淮北地区,L-CWE影响大值区位于淮北中部和江淮南部。另外,11月、12月和3月发生的R-CWE显著多于1月和2月,11月发生的L-CWE较其他月份偏多。R-CWE在全球变暖之后对应的线性增加趋势较L-CWE更显著,尤其是2010年之后R-CWE发生次数明显增多。环流分析表明,L-CWE第−4天欧亚大陆中、高纬度500 hPa附近由一对大型斜槽、斜脊主导,75°N以北地区的冷空气可由西北路径源源不断地南下,然而R-CWE同期对应的环流异常强度较L-CWE显著偏弱,冷空气主要来自75°N以南地区,乌拉尔山附近的环流系统加强程度是区分两类CWE的关键。第−2天L-CWE的西伯利亚高压强度可达1043 hPa,较R-CWE偏大5 hPa,第0天其南边界伸至31°N附近,R-CWE位于38°N附近。进一步探究发现,L-CWE发生期间在乌拉尔山附近的瞬时阻塞频率最大值为46%,西伯利亚高压指数距平从第−2天到第−1天基本处于维持状态并在第−1天达到峰值6.54 hPa,强度约为R-CWE的2倍。L-CWE前期300 hPa明显存在一条自中、高纬度地区出发向东南方向且能够传至江苏南部的罗斯贝波列,这对于在江苏发生大范围的寒潮事件十分有利。相比而言,R-CWE的罗斯贝波列传播开始时间晚1—2 d、强度更弱。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 LCWE,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 a

关 键 词：江苏 寒潮 时空变化特征 环流异常 波作用通量 

分 类 号：P467[天文地球—大气科学及气象学]