凡那比颱風為2010年侵台颱風中唯一登陸台灣的颱風，登陸期間造成台灣西南部、南部山區嚴重災情。其生命期中除了侵台期間伴隨的強風豪雨外，亦包含值得深入研究的科學議題，如：1.侵台期間降水集中於台灣西南部；2.出海後，眼牆結構重整及其對流不對稱性。本研究主要藉由WRF (Weather Research and Forecast model)數值模式的模擬結果，並且使用渦旋植入法來加強颱風的初始結構，以及進行有、無地形的敏感度實驗之模擬比對，來探討此颱風於侵台期間所具有的研究議題。
本研究使用WRF針對2010年凡那比颱風個案，以NCEP (National Centers for Environmental Prediction) 1°×1° 解析度的全球分析資料作為模式的初始場與邊界條件，透過三層巢狀網格設定（網格解析度分別為30、10、3.3公里）模擬凡那比颱風侵台期間之情形，並和觀測雷達回波圖做校驗比對。數值模擬結果顯示，模擬路徑皆掌握了颱風登陸、出海位置，使得模擬降水分布與實際觀測非常接近；此外，模式也模擬出凡那比颱風南側較強對流的不對稱結構，與登陸期間眼牆結構破壞與重整的演變過程。而地形敏感度實驗顯示，將台灣地形移除或設為平地時，颱風登陸台灣時的路徑較為平滑，強度則緩慢減弱，模擬實驗亦呈現颱風不對稱結構，但眼牆演變過程卻沒發生，此結果顯示，地形是造成眼牆結構演變的主因。
由地形與海溫敏感度實驗與環境垂直風切交互分析下，顯示環境北風風切是形成凡那比颱風對流不對稱結構的主要原因，其強對流區易發生於下風切處左側；此結果與過去探討環境垂直風切造成颱風不對稱對流結構之研究一致。另外，地形有無並不影響此環境垂直風切的產生，不過可以讓對流不對稱更加明顯；而海溫分布對颱風不對稱形成的影響則不顯著。

Typhoon Fanapi (2010) is the only landfilling case for Taiwan in 2010, and the severe disaster has been created at southern and southwestern of Taiwan. Except the heavy rainfall and extreme wind in its period of alarm from Central Weather Bureau, the scientific issues include 1) The rainfall maintain in southwestern Taiwan in the period of landfall. 2) The causes of asymmetry convective structure and the eyewall reformation after landfall. This study would be discussed the above topic by the topography and Sea Surface Temperature (SST) sensitivity experiments of Weather Research and Forecast (WRF) model simulation.
The WRF version is V3.3.1 in this study. The initial and lateral boundary conditions are based on the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) global final analysis data (1°×1°). The integration domain has a triply nested grid system with resolutions of 30, 10, and 3.3 km. The model results catch the intensity tendency and close tracks by all sensitivity experiments, especially the control run (TL). The simulation results show that due to the simulated track is quite similar with observed, leads the simulated precipitation distribution very close to the observed rainfall distribution. The model well simulated the shear induced asymmetric convection of storm and terrain induced eyewall evolution during landfall. Further, the terrain sensitivity experiments show that when removed or flatten the terrain of Taiwan, the asymmetric structure can also appear in the simulation; however, the evolution of the eyewall does not occur, this result shows that the eyewall evolution is mainly caused by the effect of the topography.
From the several sensitivity experiments results and vertical wind shear analyses, it is suggested the environmental northern vertical wind shear is the main cause to produce the asymmetry convective structure
of Fanapi. The convective cells form on the downshear side, then advert around the eye into the semicircle to the left of shear vector, thus lead a precipitation maximum forming over the downshear-left side of storm. These result is consistent with previous studies regarding the environmental vertical wind shear on the formation of the asymmetric convection of tropical cyclones. Furthermore, it is found that the asymmetric convection is not obviously influenced by the terrain, but tends to induce more asymmetric convection of the storm. The SST horizontal variation has not significant influence for the phenomena.