Use Turbulence Resolving Technique to Investigate the Characteristics of Mountain-Valley Flow and Afternoon Thunderstorm System over Complex Terrain in Taiwan

This proposal is the extension of the previous year's project. Due to the complex topography, the development of atmospheric motions over the mountainous area are difficult to resolve in the meteorological modeling that also enhance the weather forecasting capability. The objective of this study is to utilize the turbulence resolving technique to investigate the characteristics of land surface processes including the land-air interactions and land surface heating over the complex terrain in Taiwan; furthermore, to examine its affect on the dynamic and thermodynamic structures of the wind circulation systems and afternoon thunderstorm systems.The mesoscale meteorological simulations cannot resolve the turbulence scale motions. With the application of the turbulence resolving technique, we are expecting the atmospheric structures can be better resolved over the complex terrain. In this study, we will utilize the Vector Vorticity Cloud Model (VVCM) to simulate the turbulence structures. Currently, we are improving the land surface processes (Noah LSM) and soil moisture initialization process in VVCM to provide the more realistic lower boundary conditions. In addition, the Weather Research and Forecasting (WRF) model system coupled with the LES will be applied. WRF is a community model and has been widely used in the world. Because the application of the VVCM is in an idealized setup, the simulation with the WRF-LES should provide a justified result that is close to the realistic conditions.We are expecting the results from this study should be able to provide a comprehensive understanding of the characteristics of the land-air interactions, mountain-va丨丨ey flows and afternoon thunderstorms over the mountainous area.