The Analysis of Dual-Polarization Radar Data and the Simulation Research of WRF Model : Mei-yu Rainfall System on May 12, 2005.

• Main Authors: Yen-li Liu, 劉妍利
• Other Authors: 陳台琦
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/80814378465757430143

碩士 === 國立中央大學 === 大氣物理研究所 === 95 === The NCU C-band dual-polarization (C-Pol) radar parameters include the reflectivity (Zhh), the differential reflectivity (Zdr), the specific differential phase (Kdp), and the zero lag cross-correlation of horizontal and vertical wave (Rhv) can classify hydrometeor particles by using fuzzy logic method. Since the lack of airborne observations in Taiwan, we use the Ranges of polarimetric variables and temperature for various hydrometeor species delivered by P.T May and T.D. Keenan (2003) to correct the membership functions which were applied to S-Pol radar originally. Furthermore, we compare the microphysical classification of particles with WRF model and we can learn more about the difference between the different microphysical schemes in WRF model. The three research cases are Mei-yu frontal rainfall events on May 12, 2005. One is the convective precipitation at sea, another is the convective precipitation at land, and the third is the stratiform precipitation around Taipei city. The model result shows encouraging features from the Betts-Miller-Janjic cumulus parameterization run. The height of bright band from observation and simulation are very close, at 4 to 5 km. The pattern and location of hydrometeor particles are also quite similar. Three microphysical schemes outputs were also analyzed in every thirty minutes. The order magnitudes of the mixing ratio of all the hydrometeor species by WSM6 scheme are compatible with radar retrieved quantities.