臺灣區域豪雨觀測與預報實驗後續研究-TAHOPE梅雨與颱風季降雨微物理與邊界層熱動力特性之研究(總計畫及子計畫一)

This project mainly focuses on the cloud and precipitation microphysics processes of the mesoscale convective systems (MCSs) associated with the invaded typhoons and Mei-Yu systems, and the mesoscale atmosphericenvironment (especially the evolution of low-level jet, thermal and dynamical atmospheric boundary layer structures and the moisture transport) using field campaign observations and numerical simulations. During a typhoon or Mei-Yu front passes over Taiwan, the evolution of raindrop size distributions and precipitating cloud microphysics, as well as mesoscale conditions and dynamical/physical mechanisms associated with heavy orographic precipitation will be investigated using field campaign observations (e.g., wind profiler, polarimetric radar, disdrometer, etc.). For heavy rainfall cases, sensitivity tests of the planetary boundary layer parameterization, microphysics parameterization and terrain effects will be constructed using high-resolution WRF model. In addition, field campaign observations will be used to verify model simulation results. The above physical processes for the development of heavy rainfall over Taiwan will be discussed using a combination of observations and numerical simulations. During TAHOPE/TAHOPE-Phase II experiment (Taiwan-Area Heavy rain Observation and Prediction Experiment; Mei-Yu periods), we will investigate three kinds of low-level jets (synoptic-system-related low-level jet/SLLJ, barrier jet, and marine boundary layer jet/MBLJ) that could possible contribute to heavy rainfall over Taiwan: (1) the interaction between these low-level jets and terrain, (2) the relationship between them and the Mei-Yu system, and (3) their impacts on the development and structure evolution of mesoscale convective systems associated with the Mei-Yu system and physical mechanisms of precipitation. In the past three project years, we have studied the climatological characteristics of marine boundary layer jets that affect Taiwan and the relationship between the boundary layer moisture transport and heavy rainfall over Taiwan, and published3 SCI paper. In addition, for the observation analysis of raindrop size distributions and precipitation microphysics processes under different precipitation system and different season, we also have published 5 peer reviewed papers. Base on the past research, we will do in-depth study on microphysics and thermal dynamical characteristics of boundary layer during Mei-Yu and typhoon seasons.