1.Key Laboratory of Cloud-Precipitation Physics and Severe Storms,Institute of Atmospheric Physics,Chinese Academy of Sciences;2.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology;3.University of Chinese Academy of Sciences.;4.University of Chinese Academy of Sciences;5.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology
The process of making landfall of tropical cyclone Mujigae (1522) are simulated at high resolution by using WRF (Weather Research and Forecasting) Model. The verification demonstrates that the simulation agrees well with a variety of observations, especially for the track, intensity and precipitation distribution. Then the kinematic and thermodynamic structure and the wind distribution during making landfall are analyzed and the wind field is diagnosed from an azimuthal momentum budget based on the simulation data. The analysis of the budget on representative height of near-surface layer and the top of PBL (planetary boundary layer) reveal that the main contributors to the wind tendency are the radial absolute vorticity flux (VVOR) and the azimuthal pressure gradient force(VPGF) near the surface at an altitude of 0.4km. Near the top of the PBL at an altitude of 1.3km, the azimuthal pressure gradient force (VPGF) and radial advection (VVA) contributed to the acceleration of the azimuthal flow, while the inward (outward) advection of VVOR is responsible for the strengthening (weakening) of the azimuthal wind. The analysis of the azimuthally averaged fields of the budget reveal that the VVA and VVOR are main contributors to the wind tendency before making landfall of Mujigae.