Influence of microphysics schemes on radar reflectivity: Typhoon Morakot and a case during SoWMEX/TiMREX

• Main Authors: Yu-wen Chen, 陳怡彣
• Other Authors: Chung-hsiung Sui
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/01498854506992761668

碩士 === 國立中央大學 === 水文與海洋科學研究所 === 99 === In order to evaluate the influence of microphysics scheme on radar reflectivity, the single-moment microphysics scheme (Lin scheme; Lin et al., 1983) was used in the Weather Research and Forecasting (WRF) Model to provide the initial condition for QuickBeam radar simulation. Two rainfall cases were chosen in this study: Typhoon Morakot (2000UTC 7 Aug 2009) and an experiment during SoWMEX/TiMREX (1700UTC 14 Jun 2008). The simulated radar reflectivity were compared to the observed radar data (RCCG and SPOL data). At the altitude of 3 km, the frequency distribution of simulated radar reflectivity in case of the Typhoon Morakot was similar to the observation of RCCG. In case of SoWMEX/TiMREX, 60% of radar reflectivity was distributed in 20-25 dBz, which was more concentrative than the observation of SPOL(20-35 dBz). At the altitude of 7 km, the frequency distribution of radar reflectivity in case of the Typhoon Morakot was still similar to the observation of RCCG. But the frequency distribution of large value in case of SoWMEX/TiMREX was overestimate. The results of vertical mean radar reflectivity show that the simulated radar reflectivity by Lin scheme was overestimate in both cases of the Typhoon Morakot and SoWMEX/TiMREX. In addition, the simulated radar reflectivity was similar to the observation at the bottom of stratiform region. Above the altitude of 6 km, the difference between the simulation and observation of SPOL increased with height. Besides, the results of all region of convection was overestimate.