Abstract:
The process of making landfall of tropical cyclone Mujigae (1522) is simulated at high resolution using the weather research and forecasting model. The simulation was verified to agree well with a variety of observations, especially for the track, intensity, and precipitation distribution. Afterward, the kinematic and thermodynamic structures and the wind distribution while 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 the representative height of the near-surface layer and the top of the planetary boundary layer (PBL) reveals 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 0.4 km. Near the top of the PBL at an altitude of 1.3 km, the azimuthal pressure gradient force (VPGF) and radial advection (VVA) contribute to the acceleration of the azimuthal flow, while the inward (outward) advection of the VVOR is responsible for the strengthening (weakening) of the azimuthal wind. The analysis of the azimuthally averaged fields of the budget reveals that the VVA and VVOR are main contributors to the wind tendency before making landfall of Mujigae.