| Summary: | 碩士 === 國立中央大學 === 大氣物理研究所 === 96 === In the past decades, microwave sensors have become an important tool in typhoon rainfall monitoring due to the cloud transparency capacity and resolution improvement. Kidder et al. (2005) used passive microwave data, such as SSM/I, TMI and AMSU, to predict the 24-hour later tropical cyclone rainfall potential (TRaP) via a simple cyclone shift-motion assumption, along with the official cyclone track prediction results. However, their method didn’t take into account the cyclone intensity and cyclone rotation changes, which could alter the rainfall spatial patterns .
Based on the TRaP method, this research factors in the cyclone intensity changes after making landfall via an exponential decay equation(Kaplan and DeMaria, 1995). The intensity estimations reveal that the mean absolute errors (MAE) are 4.48kt and 6.73kt for plain and hill regions, respectively. In addition, the cyclone rotation effect on the rainfall patterns is considered (Liu et al., 2008), as well. The landfalling tropical cyclones in the southeastern China between 1990 to 2004 were analyzed, where their respective 6-hour later rainfall rates were predicted. The projected rainfall was verified by ground weather station data. Results reveal that the correlation is 0.68 when the shift-motions are only considered, and is 0.75 when the tropical cyclones’ intensity and rotation changes are also taken into account, it can further improve the TRaP method accuracy.
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