Investigation of Dynamic/Thermodynamic Processes of Mountain/Valley Flow and Afternoon Thunderstorm System over Complex Terrain and Its Interaction with Land Surface Hydrologic Processes in Taiwan

Due to the complex topography, the development of atmospheric motions over themountainous area is difficult to resolve in the meteorological modeling. In our previous studies, wehave developed the high resolution meteorological modeling simulation with grid resolution lessthan 1km in order to discuss the fine scale atmospheric motions over the mountainous area. In thisproposal, we will continue and extend the previous work and apply the fine scale meteorologicalmodeling technique to study the atmospheric dynamic/thermodynamic processes over the complexterrain in Taiwan, particularly focusing on the afternoon-thunderstorm system development. Theafternoon-thunderstorm system typically brings large amounts of rainfall and causes the floodproblem. In this proposal, we will also discuss the precipitation caused by the convective systemand investigate its subsequent impact on the land surface hydrologic processes including the soilmoisture variation and surface/subsurface runoff processes.The objectives of this proposal include: (1) investigations of the upslope/downslope andmountain/valley wind structures and its interaction with the land-sea breeze circulation; (2)discussions of the afternoon thunderstorm formation mechanism; (3) convection andorography induced precipitation process; (4) study the impact of the convectiveprecipitation on the land surface hydrologic processes over the mountainous area.In this study, we will utilize the Weather Research and Forecasting (WRF) model to study thefine scale structures over the mountainous area. The WRF model system coupled with the largeeddy simulation (LES) technique will be applied. To study the land surface hydrologic processes,we will utilize Noah-MP (multi-parameterization options) land surface model (LSM). Unlike NoahLSM that only considers a free drainage lower boundary condition, the Noah-MP LSM considersthe dynamically determined water table depth within the model soil layers and the lateral flow of theaquifer water, those processes are generally important over the complex terrain and on highresolutionmodel.We are expecting the results from this study should be able to provide a comprehensiveunderstanding of the development of the atmospheric dynamic/thermodynamic processes over thecomplex topography, and to figure out the formation mechanisms of the mountain/valley windstructures and how it interacts with the land-sea breeze flow as well as the processes that leads tothe formation of the afternoon thunderstorms over the mountainous area. The interaction betweenthe convective precipitation and the land surface hydrologic processes will be discussed throughthe fine scale meteorological and land surface hydrologic modeling technique.