台风“苗柏”影响下局地强降水精细化垂直结构特征观测分析  

Observational Analysis of the Fine-scale Vertical Structure of Localized Heavy Precipitation Associated with Typhoon "Merbok"

作　　者：谷欣蕊 罗亚丽[2] 肖天贵[1] 吴翀[2] 郑栋[2] GU Xinrui;LUO Yali;XIAO Tiangui;WU Chong;ZHENG Dong(College of Atmosphere Science,Chengdu University of Information Technology,Chengdu 610225,China;Chinese Academy of Meteorological Sciences,Beijing 100081,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225 [2]中国气象科学研究院,北京100081

出　　处：《成都信息工程大学学报》2022年第3期290-301,共12页Journal of Chengdu University of Information Technology

基　　金：中国气象科学研究院基本科研业务费专项资助项目(2020Z010)。

摘　　要：为研究珠三角地区强降水的云微物理特征,利用广州双偏振雷达观测数据、地面自动站降水资料、广州低频电场探测阵列探测的闪电脉冲放电事件资料及ERA5再分析资料,分析2017年6月12-13日台风“苗柏”影响下珠三角地区三处(A、B、C)局地短时强降水的精细化垂直结构特征。结果表明:珠三角内陆A、B区域的强降水由一条快速移动的东北—西南中尺度带状强回波的北段和中段产生,海岸线上C区域的强降水由一个稳定维持的准静止团状对流体产生;溶解层以下,3个区域的Z_(DR)、K_(DP)随着高度降低逐渐增大,表明其暖雨过程很活跃;3个区域40 dBz回波伸展至9 km左右,4.5~7 km处霰粒子占所有类型水凝物的面积比例均大于40%,5~13 km高度均出现闪电,表明冰相和混合相云微物理过程对强降水也有重要贡献;相比A和B,C区域溶解层以下Z_(H)频次峰值的Z_(H)值更大,近地面极端累积降水量更大,低层较大的雨滴和较高的含水量均更多,闪电脉冲放电事件频数峰值的高度也更高。这不仅由于C区域具有更丰富的水汽、更低的抬升凝结高度和自由对流高度,也与其对流体的团状形态和稳定少动有关。In order to study the cloud microphysical characteristics of heavy precipitation in the Pearl River Delta region,the Guangzhou dual-polarization radar(dual-POL) observations,precipitation data from automatic weather stations(AWSs),lightning pulse discharge events data obtained by the Guangzhou Low-frequency E-field Detection Array(LFEDA),and ERA5 reanalysis data were used to analyze the fine-scale vertical structure of three localized short-term heavy rainfall regions(A,B,C) in the Pearl River Delta under the influence of Typhoon " Merbok" on June 12-13,2017.Major findings are as follows.The heavy rainfall in the inland A and B,respectively,are produced by the northern and middle portions of a fast moving,northeast-southwest oriented mesoscale rainband,and in the coastal C by a quasi-stationary circular convective element.Below the melting layer(at approximately 5 km height),Z_(DR) and K_(DP) in the three regions gradually increase toward the ground,indicating active warm rain processes.Meanwhile,the strong reflectivities(> 40 dBZ) extend up to about 9 km,with graupel accounting for more than 40% of the hydrometeor area at4.5-7 km and lightning mostly at 5-13 km height in the three regions,indicating significant contribution of ice-and mixed-phase microphysical processes to the heavy rainfall production.Compared to A and B,precipitation in C has the modes of ZH below the melting layer at higher values,larger extreme rainfall accumulation,more occurrences of both large raindrops and high liquid water content.The lightning pulse discharge event frequency in C peaks at about 10-11 km,which is higher than those of A and B(8-9 km).Such differences are attributed to more abundant moisture,lower lifting condensation level and level of free convection in C,and also related to the circular shape and quasi-stationary feature of the convective element in C.

关 键 词：大气科学 中尺度气象学 强降水 双偏振雷达 珠三角 暖雨过程 冰相过程 

分 类 号：P458.121[天文地球—大气科学及气象学]