1814号台风“摩羯”造成浙江内陆强降水的动力特征分析  

Dynamic characteristics of inland heavy precipitation in Zhejiang induced by Typhoon Yagi(2018)

作　　者：徐亚钦 叶妍婷 刘瑞[2] 黄嘉仪 蔡晓冬 周玲丽 XU Yaqin;YE Yanting;LIU Rui;HUANG Jiayi;CAI Xiaodong;ZHOU Lingli(Jinhua Meteorological Bureau,Jinhua 321000,China;Zhejiang University,Hangzhou 310058,China;Zhejiang Meteorological Observatory,Hangzhou 310051,China)

机构地区：[1]金华市气象局,浙江金华321000 [2]浙江大学,浙江杭州310058 [3]浙江省气象台,浙江杭州310051

出　　处：《海洋气象学报》2022年第4期37-47,共11页Journal of Marine Meteorology

基　　金：国家自然科学基金项目(42105011);浙江省气象局指令性项目(2021YYZX15)。

摘　　要：采用NCEP/NCAR 0.25°×0.25°再分析资料及预报场、FY-2E云顶亮温、雷达、自动气象观测站等资料,运用风场分解、中尺度平滑滤波等方法对台风“摩羯”造成的浙江内陆局地强降水相关动力特征进行分析。结果表明:(1)台风中心环流由低层到高层呈现向西南方向倾斜的非对称结构,台风前侧(浙闽赣交界处)的低涡对中高层整体环流分布造成了一定影响。(2)在台风移动方向(低层垂直风切变顺切变方向)前侧,925 hPa相对入流辐合与700 hPa相对出流辐散形成耦合。(3)边界层辐合及地面辐合线较长时间维持在台风移动方向前侧,正涡度柱随台风移动西传,在浙中形成低层辐合和涡度叠加效应,有利于浙中内陆局地强降水。(4)偏东气流的风速辐合、边界层相对入流以及之后西南气流的增强对浙中内陆边界层辐合的长时间维持起到一定作用。此外,地形对浙江内陆局地强降水也起了增幅作用。Wind partitioning and Shuman-Shapiro filtering are used to analyze the dynamic characteristics of the local inland heavy precipitation in Zhejiang induced by Typhoon Yagi(2018)based on NCEP/NCAR 0.25°×0.25°reanalysis data and forecast products,black-body temperature(TBB)from FY-2E meteorological satellite,and observations from radars and automatic meteorological stations.The results are as follows.(1)A vortex located in front of the typhoon(junction of Zhejiang,Fujian,and Jiangxi provinces)has a certain effect on the circulation in the middle and upper level,resulting in an asymmetric structure of typhoon circulation with typhoon center tilting to the southeast from low to high level.(2)Convergence at 925 hPa caused by inflow has a coupling effect with divergence at 700 hPa caused by outflow in front of the typhoon(along the downshear of low-level vertical wind shear).(3)The boundary layer convergence and surface convergence line are maintained in front of the typhoon for a long time and the westward movement of positive vorticity column with the typhoon leads to low-level convergence and duplicate effect in central Zhejiang,which is conducive to the inland heavy precipitation there.(4)The convergence of easterly flow,inflow in boundary layer,and the strengthening of southwesterly flow all contribute to the long-term maintaining of boundary layer convergence in central Zhejiang.In addition,the topographic effect also has a positive effect on the local inland heavy rain in central Zhejiang.

关 键 词：台风 局地强降水 边界层辐合 非对称结构 

分 类 号：P444[天文地球—大气科学及气象学] P426.6