冷涡背景下辽宁龙卷气候特征和环境条件  

Climatic characteristics and environmental conditions of tornadoes in Liaoning under the background of cold vortex

作　　者：才奎志 姚秀萍[2,3] 孙晓巍 程攀[1] CAI Kuizhi;YAO Xiuping;SUN Xiaowei;CHENG Pan(Liaoning Warning Center of Meteorological Disaster Monitoring,Shenyang 110166,China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;China Meteorological Administration Training Centre,Beijing 100081,China;Institute of Atmospheric Environment,China Meteorological Administration,Shenyang 110166,China;Liaoning Meteorological Observatory,Shenyang 110166,China)

机构地区：[1]辽宁省气象灾害监测预警中心,沈阳110166 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]中国气象局气象干部培训学院,北京100081 [4]中国气象局沈阳大气环境研究所,沈阳110166 [5]辽宁省气象台,沈阳110166

出　　处：《气象学报》2022年第1期82-92,共11页Acta Meteorologica Sinica

基　　金：国家自然科学基金重点项目(42175008、42030611);辽宁省自然科学基金指导计划项目(2019-ZD-0855);中国气象局沈阳大气环境研究所联合开放基金项目(2021SYIAEKFMS15);辽宁省气象局关键技术项目(LNGJ201908)。

摘　　要：为了研究冷涡与辽宁龙卷的关系,揭示冷涡背景下辽宁龙卷发生的特征,利用1951-2020年辽宁省龙卷观测和灾情数据以及欧洲中期天气预报中心ERA5大气再分析资料,收集整理冷涡背景下辽宁龙卷个例,对比冷涡背景下EF2-4级(EF2+)和EF0-1级(EF1-)龙卷物理量参数的差异。结果表明:(1)冷涡背景下辽宁龙卷主要出现在辽宁沿海地区和中部、北部平原。冷涡背景下辽宁龙卷主要发生在冷涡东南和西南象限,易出现在冷涡增强阶段。龙卷与冷涡中心平均距离近900 km,冷涡越强,龙卷出现位置离冷涡中心越远,反之越近。(2)1951-2020年冷涡背景下辽宁龙卷个数接近总样本的50%,龙卷个数与冷涡日数呈正相关;冷涡背景下辽宁龙卷发生位置与冷涡中心的距离具有明显的月变化,8月距离达到最近。(3)对比冷涡背景下EF2-4级(EF2+)和EF0-1级(EF1-)龙卷,EF2+龙卷比EF1-龙卷大气热力和动力学环境参数的强度分别高出40%和65%以上。对比冷涡背景下辽宁龙卷和热带气旋龙卷发现,冷涡龙卷的对流有效位能是热带气旋龙卷的3倍左右,但风暴相对螺旋度只有热带气旋龙卷的1/2。(4)能量螺旋度和龙卷参数可区分冷涡背景下辽宁龙卷等级,远低于美国龙卷综合参数阈值。可见,冷涡强度、位置和辽宁龙卷的产生关系密切,冷涡背景下EF2+龙卷物理量参数明显大于EF1-龙卷,冷涡背景下辽宁龙卷与热带气旋龙卷的热力、动力学环境参数有较大差异,调整能量螺旋度和龙卷参数阈值标准,可以提高冷涡背景下辽宁强龙卷发生的命中率。In order to study the relationship between cold vortex and tornado in Liaoning,the characteristics of tornado occurrence in Liaoning under the background of cold vortex are investigated.Using tornado observations and weather disasters data in Liaoning province and the ERA5 atmospheric reanalysis data of the European Center for Mediumrange Weather Forecasts(ECMWF)from1951 to 2020,tornado cases in Liaoning under the cold vortex background are collected and sorted out.Differences between the physical parameters of EF2-4(EF2+)and EF0-1(EF1-)tornadoes under the cold vortex background are compared.The results are as follows.(1)Tornadoes under the cold vortex background mainly occur in the coastal area and the central and northern plain of Liaoning province.The average distance between the tornado and the center of the cold vortex is nearly 900 km.The stronger the cold vortex,the farther its center is from the tornado;the weaker the cold vortex,the closer the distance between the center of the cold vortex and the tornado.Under the background of cold vortex,tornadoes in Liaoning province mainly occur between the southeast and southwest quadrants of the cold vortex,and frequently occur in the enhancement stage of the cold vortex.(2)The number of tornados in Liaoning province in the cold vortex background accounts for nearly 50%of the total samples from 1951 to 2020,and the number of tornados is positively correlated with the number of cold vortex days.The distance between the mean location of the tornadoes in Liaoning under the background of the cold vortex and the average center of the cold vortexes has obvious monthly changes with the closest distance in August.(3)Comparing EF2-4(EF2+)with EF0-1(EF1-)tornadoes under the background of cold vortex,the thermal and dynamic environmental parameters of EF2+tornadoes are 40%and 65%higher than that of EF1-tornadoes.Comparing the tornadoes in Liaoning under the background of cold vortex and tropical cyclone tornadoes,it is found that the convective available potential energy of

关 键 词：冷涡 龙卷 辽宁 能量螺旋度 龙卷参数 

分 类 号：P445[天文地球—大气科学及气象学] P456