气象学报2012，Vol.70Issue(1)：15-29,15.
浙江沿海登陆台风结构特性的多普勒雷达资料分析
Study of the structure and characteristics associated with landfalling typhoons on the southeastern coast of Zhejiang province in China using Doppler radar data
摘要
Abstract
This study investigated temporal and spatial variations of the reflectivity and precipitation structure within 300 km radius of typhoon center by using the reflectivity data taken from the Doppler radars located in Zhejiang province. Three typhoons making landfall along the southeastern coast of Zhejiang province in China have been selected to examine the changes of the precipitation distribution from 6 h before landfall to 7 h after landfall. The three-dimensional wind fields are retrieved from the Wenzhou Doppler radar data using the 4D-Var wind retrieval technology. The 3D structure of the mesoscale convective system producing the most severe heavy rainfall at Yunyan and Changchan is analyzed with the single-Doppler radar retrieved wind and radar reflectivity observed by the Wenzhou Doppler radar. The results show that the stronger the typhoon intensity is, the bigger the reflectivity of the middle and low levels is, and the more severe the mesoscale convective system and the precipitation rate are. The axisymmetric component of typhoon echo (rainfall), represented by the radial distribution of the azimuthal mean reflectivity, reveals that echo (rainfall) spreads outward from the typhoon eyewall before landfallling. The mean echo (rainfall rate) in the inner-core region increases abruptly, accompanied with the rapid contraction of the precipitation areas toward typhoon center when typhoons are approaching the coast. The mean rainfall rate in the typhoon eyewall will intensify after landfall. The single-Doppler radar retrieved wind fields indicate that, at 1 h after typhoon landfailing, with the enhanced convergent (divergent) wind fields in the low (upper) levels, the tilted upward movement in the mesoscale convective system is enhanced and the precipitation rate is increased obviously. The typhoon intensity is proportional to the increases of the precipitation rate. The stronger the typhoon intensity is, the bigger the vertical winds shear value is. The area of the maximum vertical wind shear value is corresponding to that of the most severe heavy rainfall. The obvious increase of the vertical wind shear value plays an important role in the enhancement and sustaining of the mesoscale convective system in spiral rain bands of landfalling typhoon.关键词
登陆台风/回波变化/降水分布/风场反演Key words
Landfailing typhoon/Echo change/Precipitation distribution/Wind retrieval分类
天文与地球科学引用本文复制引用
赵放,冀春晓,高守亭,刘黎平..浙江沿海登陆台风结构特性的多普勒雷达资料分析[J].气象学报,2012,70(1):15-29,15.基金项目
国家自然科学基金重点项目(90815028)、公益性行业(气象)科研专项(GYHY200706020、GYHY201006007)、灾害国家重点实验室开放课题(2008LASW-A01). （90815028）
