Finescale Spiral Rainbands Modeled in a High-Resolution Simulation of Typhoon Rananim (2004)

作     者：李青青 端义宏 余晖 傅刚 LI Qingqing;DUAN Yihong;YU Hui;FU Gang

作者机构：Shanghai Typhoon InstituteLaboratory of Typhoon Forecast Technique/CMA National Meteorological CentreChina Meteorological Administration Laboratories of Ocean-Atmosphere Interaction and Climate and Physical OceanographyDepartment of Marine MeteorologyOcean University of China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2010年第27卷第3期

页      面：685-704页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：supported by the National Basic Research Program of China (2009CB421505) the National Natural Science Foundation of China under Grants Nos.40730948 the National Natural Science Foundation of China under Grants Nos.40575030 the National Natural Science Foundation of China under Grants Nos.40705024 the Shanghai Typhoon Foundation (2009ST09) supported by the National Nature Science Foundation of China under the Grant No.40675060 the program of the Ministry of Science and Technology of the People's Republic of China (2006AA09Z151) the program of China Meteorological Administration(GYHY200706031) 

主　　题：finescale rainbands dynamic and thermodynamic structure boundary layer instabilities Typhoon Rananim 

摘      要：Finescale spiral rainbands associated with Typhoon Rananim （2004） with the band length ranging from 10 to nearly 100 km and band width varying from 5 to 15 km are simulated using the Fifth-Generation NCAR/Penn State Mesoscale Model （MM5）. The finescale rainbands have two types： one intersecting the eyewall and causing damaging wind streaks, and the other distributed azimuthally along the inner edge of the eyewall with a relatively short lifetime. The formation of the high-velocity wind streaks results from the interaction of the azimuthal flow with the banded vertical vorticity structure triggered by tilting of the horizontal vorticity. The vertical advection of azimuthal momentum also leads to acceleration of tangential flow at a relatively high Mtitude. The evolution and structures of the bands are also examined in this study. Further investigation suggests that the boundary inflection points are related tightly to the development of the finescale rainbands, consistent with previous findings using simple symmetric models. In particular; the presence of the level of inflow reversal in the boundary layer is a crucial factor controlling the formation of these bands. The near-surface wavy peaks of vertical vorticity always follow the inflection points in radial flow. The mesoscale vortices and associated convective updrafts in the eyewall are considered to strengthen the activity of finescale bands, and the updrafts can trigger the formation of the bands as they reside in the environment with inflow reversal in the boundary layer.