雨滴谱及双偏振雷达等资料在一次强降水过程中的应用  

Application of Raindrop Spectrum and Dual Polarization Radar Data to a Heavy Rain Process

作　　者：申高航 高安春 李君 SHEN Gaohang;GAO Anchun;LI Jun(Junan County Meteorological Station of Shandong Province,Junan 276600;Linyi Meteorological Office of Shandong Province,Linyi 276004;Zibo Meteorological Office of Shandong Province,Zibo 255025)

机构地区：[1]山东省莒南县气象局,莒南276600 [2]山东省临沂市气象局,临沂276004 [3]山东省淄博市气象局,淄博255025

出　　处：《气象》2021年第6期737-745,共9页Meteorological Monthly

基　　金：山东省自然科学基金(ZR2016DM20);山东省气象局预报员专项(SDYBY2018-14);临沂市气象局自立课题(2019lyqx06)共同资助。

摘　　要：2019年8月9日20时至13日20时,受西风槽和台风利奇马的共同影响,山东省出现了大范围的强降水,其中心在章丘站。利用多源资料研究台风雨带强降水的微物理结构特征,分析了强降水过程中章丘站的分钟降水量、雨滴谱、双偏振多普勒雷达、风廓线雷达等资料。分析发现:本次降水过程开始阶段,存在明显的冷云降水机制。降水过程中雨滴的尺度谱随时间存在明显变化。降水较强时段,雨滴谱较宽,呈现出明显的双峰结构,直径大于1 mm的雨滴数序列与分钟降水量序列相关系数达到0.956 8;降水减弱时段,谱宽逐渐变窄,呈现出明显的单峰结构,直径大于1 mm的雨滴数变少。雷达回波高度较高时段,直径大于1 mm的雨滴数比例增大,谱宽较大,并出现多峰分布。强的湿湍流团可以形成差分反射率因子大值区,它既不对应于强对流,也不对应于地面大雨滴,是由上升和下沉气流引起的湿湍团变形以及其他原因综合导致的。降水较强时段,在风廓线时间剖面0.9~1.4 km高度,出现一个风向和风速突变的薄层结构;对应该薄层,分钟雨量最强,直径大于1 mm雨滴数的比例明显偏大。分析结果为了解台风强降水的滴谱特征和微物理结构提供了参考依据。From 20:00 BT 9 to 20:00 BT 13 August 2020,due to the combined effects of the westerly trough and the Typhoon Lichma,large-scale severe precipitation occurred in Shandong Province.The center of the severe precipitation was at Zhangqiu Station.In order to use multi-source data to study the microphysical structure characteristics of heavy rainfalls in the typhoon rain belt,this paper analyzes the data of minutely precipitation,raindrop spectrum,dual polarization Doppler radar,wind profiler radar,etc.during the severe rainfall process at Zhangqiu Station.The results show that there was an obvious cold cloud precipitation mechanism at the beginning of this precipitation process.During the precipitation,the scale spectrum of raindrops changed significantly with time.During the period of severe precipitation,the spectrum of raindrops was broad,showing an obvious bimodal structure.The correlation coefficient between the sequence of raindrop numbers with a diameter greater than 1 mm and the sequence of minutely precipitation reached 0.956 8.However,during periods of weakening precipitation,the spectrum of raindrops gradually narrowed,showing a single-peak structure clearly,and the number of raindrops with a diameter greater than 1 mm decreased.When the radar echo height was high,the proportion of raindrops with a diameter greater than 1 mm increased,the raindrop spectrum was wider,and the multimodal distribution appeared.Strong wet turbulence clusters formed a large value area of the differential reflectance factor(Z_(DR)),which neither corresponded to severe convection nor to surface heavy raindrops.This was caused jointly by the deformation of the wet turbulence resulting from updraft,downdraft and other reasons.During heavier precipitation, a thin layer structure with abrupt changes in wind direction and wind speed appeared in the time crosssection of wind profile in the 0.9-1.4 km height.Corresponding to the thin layer,the minutely rainfall was the heaviest,and the proportion of raindrops with a diameter greater than

关 键 词：雨滴谱 双偏振多普勒雷达 台风强降水 

分 类 号：P412[天文地球—大气科学及气象学]