4—9月东北大陆型冷涡消亡方式及其统计特征  

Decay processes and statistical characteristics of continental Northeast China Cold Vortex from April to September

作　　者：范子琪 朱科锋 薛明[1,3] FAN Ziqi;ZHU Kefeng;XUE Ming(Key Laboratory of Mesoscale Severe Weather/Ministry of Education and School of Atmospheric Sciences,Nanjing University,Nanjing 210023,China;CMA Key Laboratory of Transportation Meteorology,Nanjing Joint Institute for Atmospheric Science,Nanjing 210041,China;Center for Analysis and Prediction of Storms,School of Meteorology University of Oklahoma,Norman 73072,USA)

机构地区：[1]南京大学中尺度灾害性天气教育部重点实验室/大气科学学院,南京210023 [2]南京气象科技创新研究院/中国气象局交通气象重点开放实验室,南京210041 [3]美国强风暴分析预报中心/俄克拉何马大学气象学院,诺曼73072

出　　处：《气象学报》2023年第5期727-740,共14页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目(41730965);国家重点研发计划重点专项(2018YFC1507303)。

摘　　要：利用ERA-Interim再分析数据,主观识别了2009—2018年4—9月东北冷涡,并根据冷涡所在位置将其客观聚类为5类,其中3类大陆型冷涡主要影响中国东北地区,称为西北类、东北类和东南类冷涡。东北冷涡的消亡方式主要有2种,一是系统高层受非绝热加热侵蚀,二是被平流层高位涡源再吸收。对比分析非绝热消亡和再吸收消亡方式3类大陆型冷涡统计特征的差异及原因。结果表明:(1)西北类和东南类冷涡以非绝热消亡为主而东北类冷涡以再吸收消亡为主;(2)再吸收消亡冷涡强度一般强于非绝热消亡冷涡,这主要是由于前者的北侧平流层高位涡源持续向冷涡系统补充高值位涡,而后者强度不断被降水潜热释放削弱;(3)非绝热消亡冷涡持续时间比再吸收消亡冷涡长,且前者消亡阶段时间占生命期的比例更大;(4)降水和高空槽与冷涡的位置关系是影响冷涡消亡的主要因素。在冷涡气旋环流内部接近冷涡中心的较强降水能直接侵蚀高层冷涡内核区,导致其非绝热消亡;冷涡位于高空槽前或槽底有利于冷涡向北平流以被高位涡源再吸收而消亡。The Northeast China Cold Vortex(NCCV)is a major precipitation-producing weather system in northern China.Based on the ERA-Interim reanalysis data,the NCCV cases from April to September during 2009—2018 are identified and objectively clustered into 5 categories according to the location of the NCCV center.Among them,the northwest type,northeast type and southeast type continental NCCVs,named based on their locations,have significant impacts on northern China.The NCCV decay mainly involves two processes:The erosion of upper level PV(potential vorticity)by diabatic heating and reabsorption of the vortex PV back into the stratospheric reservoir.Statistical characteristics of the three types of continental NCCV that decay in the above two ways respectively are compared and analyzed.It is found that:(1)The decay of the northwest and southeast vortexes is mostly caused by diabatic processes,while the decay of the NCCVs is mostly attributed to reabsorption;(2)the intensity of the reabsorption decay type is generally stronger than that of diabatic decay type,as the north stratospheric reservoir is closer to the former.Besides,the latter is continuously weakened by latent heat release associated with precipitation;(3)the lifetime as well as the fraction of the decay phase for the diabatic decay type are longer than those of reabsorption decay type;(4)the location of the high-level trough relative to the NCCV and precipitation within the NCCV are two main factors that impact the NCCV decay.Strong precipitation near the NCCV center can directly erode the core of the vortex,resulting in diabatic decay.When the NCCV is ahead of or at the bottom of the highlevel trough,the NCCV can be easily advected northward,leading to its absorption by the stratospheric reservoir.

关 键 词：东北冷涡 统计特征 再吸收消亡 非绝热消亡 位涡 

分 类 号：P468[天文地球—大气科学及气象学]