多单体强风暴影响下的一次强降水超级单体演变特征分析  

Evolution Characteristics of Heavy Precipitation Supercell Under the Influence of the Multi-Cell Strong Storm

作　　者：陈磊 王福侠[2,4] 尉英华 花家嘉[1,2] 何丽华 侯书勋 CHEN Lei;WANG Fuxia;WEI Yinghua;HUA Jiajia;HE Lihua;HOU Shuxun(CMA Xiong’an Atmospheric Boundary Layer Key Laboratory,Hebei,Xiong’an New Area 071800;Key Laboratory of Meteorology and Ecological Environment of Hebei Province,Shijiazhuang 050021;Tangshan Meteorological Observatory of Hebei Province,Tangshan 063000;Hebei Meteorological Observatory,Shijiazhuang 050021;Tianjin Meteorological Observatory,Tianjin 300074)

机构地区：[1]中国气象局雄安大气边界层重点开放实验室,河北雄安新区071800 [2]河北省气象与生态环境重点实验室,石家庄050021 [3]河北省唐山市气象台,唐山063000 [4]河北省气象台,石家庄050021 [5]天津市气象台,天津300074

出　　处：《气象》2024年第8期966-980,共15页Meteorological Monthly

基　　金：中国气象局创新发展专项(CXFZ2024J025);河北省社会公共事业创新专项(23375401D);河北省气象局科研开发项目(20ky37);唐山市科技计划项目(19150261E)共同资助。

摘　　要：利用天津多普勒天气雷达资料、常规探测资料、地面自动站资料、ERA5再分析资料和VDRAS数据等,对2017年6月19日发生在冀东地区由多单体强风暴引领下的一次罕见的强降水超级单体风暴进行分析,重点探讨了超级单体风暴的演变特征和维持机制。结果表明,海风锋和多单体强风暴的阵风锋及其所围成的低层“舌”状高温、高湿区为超级单体风暴形成提供了较好的动力和热力条件,当对流单体移入“舌”区之后,快速发展为超级单体并一直沿着多单体强风暴的出流边界向东南方向移动。缓慢减弱的多单体强风暴所提供的相对“稳定”的阵风锋不仅为超级单体发展和维持提供了长时间的动力条件,而且还为其移动提供了引导作用,这对于强对流天气短时临近预警有很好的指示意义。在超级单体形成之初,受多单体强风暴冷池出流影响,近地面偏南风转为较强的偏东风,中尺度环境配置发生了明显改变,0~6 km垂直风切变增大到27 m·s^(-1)且0~3 km垂直风切变增大到17~19 m·s^(-1)是中气旋形成的主要原因;其次,辐合线上较强的垂直涡度平流也有利于中气旋形成和维持。此次超级单体中气旋始于低层,通过VDRAS数据得到的0~3 km低层垂直风切变始终维持在20 m·s^(-1)左右,斜压涡生作用明显,为超级单体的发展和维持提供了较大的、长时间的水平涡度输入。超级单体形成和发展成熟阶段,风暴相对螺旋度(SRH)在140~171 m^(2)·s^(-2),大部分时段在150 m^(2)·s^(-2)以上,而在超级单体形成之前和接近消散阶段,SRH明显小于150 m^(2)·s^(-2),表明SRH对于超级单体发生发展有较为明确的指示意义。此次过程冷池出流先于超级单体形成,使得入流区辐合抬升加强,有利于超级单体的发展和维持,另外超级单体中不断有单体从母暴中分裂并减弱东移,一定程度上削弱了超级单体的强烈发展,使得下沉出流不Based on the Tianjin Doppler radar data,conventional observation,ground automatic station meteorological data,ERA5 reanalysis data and VDRAS data,a rare heavy precipitation(HP)supercell storm which was guided by a multi-cell strong storm occurred in the east of Hebei Province on 19 June 2017.In this paper,the evolution characteristics and maintenance mechanism of this supercell storm are mainly analyzed.The results indicate that the sea breeze front and the gust front of the multi-cell strong storm,the tongue-shaped high temperature and high humidity area in the lower layer provided better thermal and dynamic conditions for the formation of the supercell.When the convection cell moved into the tongue area,it rapidly developed into a supercell and moved southeastward along the outflow boundary of multi-cell strong storm.The relatively stable gust front fed by the slowly weakening severe thunderstorm not only provided long-time dynamic conditions for the development and maintenance of supercell,but also guided its movement.This is of great significance for the short-time and nowcasting of convective weather.At the beginning of the formation of supercell,affected by the outflow of multi-cell strong storm cold pool,the southerly winds near the ground turned to stronger easterly winds,changing the configuration of mesoscale environment significantly.The vertical wind shear of 0-6 km increased to 27 m·s^(-1)and the shear of 0-3 km increased to 17-19 m·s^(-1),which was the main reason for the rapid formation of mesocyclone.The strong vertical vorticity advection on the convergence line was also conducive to the formation and maintenance of mesocyclone.The reason why the cyclone in supercell started at the lower level is that the vertical wind shear of 0-3 km obtained from VDRAS data was always about 20 m·s^(-1),the baroclinic vortex effect was obvious,providing a large and long-time horizontal vorticity input for the development and maintenance of supercell.During the formation and development of supercell,the storm

关 键 词：超级单体 中气旋 阵风锋 垂直风切变 

分 类 号：P458[天文地球—大气科学及气象学] P433