海棠颱風(2005)侵台路徑之數值模擬研究

• Main Authors: Wu Meng Hsun, 吳孟勳
• Other Authors: 汪建良
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/17696757538898973917

碩士 === 國防大學中正理工學院 === 應用物理研究所 === 95 === In this research, the evolution of Supertyphoon Haitang(2005) passing through Taiwan is simulated by using WRF model with three nesting grids (45 km、15 km ,and 5 km). In order to understand how cumulus parameterization schemes and Taiwan terrain height affect the structure and track of the typhoon, a series of experiments has been carried out. Different cumulus parameterization schemes result in different convective structures and typhoon tracks. Although no cumulus parameterization scheme is needed in the 5-km resolution mode, but as its boundary conditions come from the 15-km resolution mode using cumulus parameterization, the simulated typhoon tracks are affected by the choice of schemes. In this case, the experiment using the Kain-Fristsch scheme has the track closest to the best track. From Taiwan terrain height experiments, the results show that the higher the Taiwan terrain height, the more distinct looping track when typhoon is close to Taiwan. If Taiwan terrain height is high enough, the track of the typhoon passing through Taiwan changed from continuous to discontinuous. The physical processes associated with the looping track of Supertyphoon Haitang may be resulted from three mechanisms. First, the looping track may be associated with the low-level northerly jet due to topographical effects, consistent with other studies. Second, the looping track may be associated with the interaction of the upper- and lower-level circulations, as the lower-level circulation alone is affected by Taiwan’s topography and has a looping track. Finally, the looping track may be associated with the typhoon’s convective structure. When Supertyphoon Haitang moves near Taiwan, the orographic lifting may enhance local convection and then forces the typhoon to have a looping track.