Summary: | 碩士 === 國立中央大學 === 大氣物理研究所 === 96 === In this study, we developed an objective method to analyze typhoon tracks by computer programs. The main purpose of this study is to search historical typhoon tracks in a faster and more convenient manner.
We used tropical cyclone best-tracks data over the Western North Pacific from Joint Typhoon Warning Center (JTWC). This method can determine the resemblance between two arbitrary tracks by calculating their distance, and find out the similar tracks by comparing the distances. It can also classify the tracks by limited distances and ranges.
The results show that this method is capable of finding the most similar typhoon tracks to TY09W MATSA and TY15W KHANUN from the total of 25 tracks in 2005. Furthermore, those pairs of short distances between each others are found to have good similarities in lengths, shapes, and locations.
After analyzing tracks resemblance, we used this method to classify tracks by their passages. One type of classification is type-north, which includes 20 typhoon tracks. The other one is type-south, which includes 34 typhoon tracks. The rainfall pattern associated with the type-north typhoons is completely different compared with those from type-south typhoons. For type-north tracks, there are more rainfall in north Taiwan, especially in northwest, such as mountain areas in Taoyuan, Hsinchu, and Miaoli than other places. For type-south tracks, there are more rainfall in east Taiwan, such as Hualien and Taitung, and in southwest Taiwan, such as Kaohsiung and Pintung than other areas.
To sum up, this method is capable of finding the most similar typhoon tracks form historical typhoon tracks for a given tracks, and classifying the tracks by some limits for statistics study. Furthermore, we can also apply this method to predict calamities by using the information of historical typhoons.
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