Evaluation of Two Initialization Schemes for Simulating the Rapid Intensification of Typhoon Lekima (2019)  

作　　者：Donglei SHI Guanghua CHEN Ke WANG Xinxin BI Kexin CHEN 

机构地区：[1]Center for Monsoon System Research,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Meteorological Disaster,Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,China

出　　处：《Advances in Atmospheric Sciences》2020年第9期987-1006,共20页大气科学进展（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41775063 and 41975071)。

摘　　要：Two different initialization schemes for tropical cyclone(TC)prediction in numerical models are evaluated based on a case study of Typhoon Lekima(2019).The first is a dynamical initialization(DI)scheme where the axisymmetric TC vortex in the initial conditions is spun up through the 6-h cycle runs before the initial forecast time.The second scheme is a bogussing scheme where the analysis TC vortex is replaced by a synthetic Rankine vortex.Results show that although both initialization schemes can help improve the simulated rapid intensification(RI)of Lekima,the simulation employing the DI scheme(DIS)reproduces better the RI onset and intensification rate than that employing the bogussing scheme(BOG).Further analyses show the cycle runs of DI help establish a realistic TC structure with stronger secondary circulation than those in the control run and BOG,leading to fast vortex spinup and contraction of the radius of maximum wind(RMW).The resultant strong inner-core primary circulation favors precession of the midlevel vortex under the moderate vertical wind shear(VWS)and thus helps vortex alignment,contributing to an earlier RI onset.Afterwards,the decreased vertical shear and the stronger convection inside the RMW support the persistent RI of Lekima in DIS.In contrast,the reduced VWS is not well captured and the inner-core convection is weaker and resides farther away from the TC center in BOG,leading to slower intensification.The results imply that the DI effectively improves the prediction of the inner-core process,which is crucial to the RI forecast.

关 键 词：numerical simulation initialization scheme tropical cyclone intensity 

分 类 号：P444[天文地球—大气科学及气象学]