中低纬度系统相互作用过程的中尺度风场分析  

Analysis of the Mesoscale Wind Field in the Interaction Between Mid-and Low-latitude Systems

作　　者：李君 贾瑞 王俊 胡晓琳[1,3] LI Jun;JIA Rui;WANG Jun;HU Xiaolin(Key laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China;Shandong Weather Modification Office,Jinan 250031,China;Zibo Meteorological Bureau of Shandong Province,Zibo,Shandong 255000,China)

机构地区：[1]山东省气象防灾减灾重点实验室,山东济南250031 [2]山东省人民政府人工影响天气办公室,山东济南250031 [3]淄博市气象局,山东淄博255000

出　　处：《热带气象学报》2024年第2期198-207,共10页Journal of Tropical Meteorology

基　　金：山东省气象局引导类项目(2021SDYD40);山东省气象局预报员专项(SDYBY2019-08)共同资助。

摘　　要：以山东济南和滨州两部S波段多普勒雷达的观测数据为基础,采用直接合成的方法,反演台风“利奇马”和西风槽相遇引发极端降水过程的中尺度系统三维风场。(1)冷暖空气交汇产生的切变线长时间维持是西风槽与台风相互作用过程中产生极端降水的关键,暖空气先进后退,表现为东南气流和西北气流先后越过雷达站,垂直方向出现复合切变;(2)最强上升运动出现在对流单体回波梯度最大的区域,最大下沉运动出现在回波顶下风方,中低层回波中心均为弱风速区;(3)发展中的对流单体各层均有气旋式入流,成熟的对流单体高层出流有反气旋式出流;(4)风垂直切变是雨团降水增幅的主要影响因素,成熟期的雨团具有低质心对流单体风暴的结构形态,垂直运动达到最强。Based on the observation data from two dual S-band Doppler radars in Jinan and Binzhou,this paper uses the method of direct synthesis to retrieve a 3-dimensional mesoscale wind field for an extreme precipitation caused by the convergence between Typhoon Lekima and a westerly trough.The results are shown as follows.(1)The long-term maintenance of a shear generated by the convergence of cold and warm airflows in the interaction between the westerly trough and the typhoon is the key to the extreme precipitation.The warm airflow advances first and then retreats,a southeast and a northwest airflow cross the radar station successively,and within a small time frame a composite shear occurs vertically.(2)Maximum updraft occurs in the windward area of convective cells with the largest gradient of reflectivity,and maximum downdraft appears downwind the echo top.It is a weak wind area near the echo center at the mid-and low-levels;(3)There are cyclonic inflows at all layers of developing convective cells and anti-cyclonic outflows at the upper layer of mature convective cells.(4)Vertical wind shears are a main factor affecting the increase of precipitation in rain clusters,and mature rain clusters are so structured that their convective cells are low-centroid,and vertical motion is the strongest.

关 键 词：中低纬度系统相互作用 极端降水 利奇马 中尺度风场 双多普勒雷达 

分 类 号：P412[天文地球—大气科学及气象学]