Azimuthal Variations of the Convective-scale Structure in a Simulated Tropical Cyclone Principal Rainband  

作　　者：Yue JIANG Liguang WU Haikun ZHAO Xingyang ZHOU Qingyuan LIU 

机构地区：[1]Key Laboratory of Meteorological Disaster of Ministry of Education,Nanjing University of Information Science and Technology,Nanjing 210044,China [2]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China [3]Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences,Fudan University,Shanghai 200433,China [4]Nanjing Joint Institute for Atmospheric Sciences,Nanjing 210009,China

出　　处：《Advances in Atmospheric Sciences》2020年第11期1239-1255,共17页大气科学进展（英文版）

基　　金：the National Basic Research Program of China(Grant No.2015CB452803);the National Natural Science Foundation of China(Grant Nos.41730961,41675051,41675009,41675072,41922033 and 41905001);the Open Research Program of the State Key Laboratory of Severe Weather(Grant No.2019LASWA02).

摘　　要：Previous numerical simulations have focused mainly on the mesoscale structure of the principal rainband in tropical cyclones with a relatively coarse model resolution.In this study,the principal rainband was simulated in a semi-idealized experiment at a horizontal grid spacing of 1/9 km and its convective-scale structure was examined by comparing the convective elements of the simulated principal rainband with previous observational studies.It is found that the convective scale structure of the simulated principal rainband is well comparable to the observation.The azimuthal variations of the convective scale structure were examined by dividing the simulated principal rainband into the upwind,middle and downwind portions.Some new features are found in the simulated principal rainband.First,the overturning updraft contains small-scale rolls aligned along the inward side of the outward-leaning reflectivity tower in the middle portion.Second,the inner-edge downdraft is combined with a branch of inflow from the upper levels in middle and downwind portions,carrying upper-level dry air to the region between the overturning updrafts and eyewall,and the intrusion of the upper-level dry air further limits the altitude of the overturning updrafts in the middle and downwind portions of the principal rainband.Third,from the middle to downwind portions,the strength of the secondary horizontal wind maximum is gradually replaced by a low-level maximum of the tangential wind collocated with the low-level downdraft.

关 键 词：azimuthal variations principal rainband tropical cyclone WRF-LES simulation 

分 类 号：P444[天文地球—大气科学及气象学] P426.62