| 摘要: | 台灣位於熱帶氣旋活躍的西北太平洋地區，每年約有30 個颱風生成於此區域，平均3 至4 個颱 風會侵襲台灣，提供了台灣夏季60%的降雨量。台灣面積不大，但具有交錯複雜且高聳的地形，每 當颱風接近台灣，地形與環流的交互作用會使颱風產生很大的變化，例如路徑的改變、移動的速度、 結構的破壞、登陸位置與地形交互作用的降雨，都是颱風預報上的不確定因素，使得預報及防災作 業上有一定的難度。過去已有研究發現環境垂直風切會讓颱風產生不對稱對流結構，並於下風切處 的區域造成強降水；然而侵台颱風強度發展的預測，仍然是相當重要而且困難的一個環節。如這兩 年重創台灣的蘇迪勒颱風(2015)、杜鵑颱風(2015)、尼伯特颱風(2016)、莫蘭蒂颱風(2016)、梅姬颱風 (2016)，幾乎都是以強烈颱風或中度颱風上限之強度侵襲台灣，且其中不乏快速增強的個案。 本研究計畫之研究重點為探討閃電資料對於颱風強度發展、結構變化與颱風受地形影響所引發之 深對流特徵研究。學術研究上將探討颱風內核對流爆發對於快速增強的關係，希望透過閃電資料的 使用能對西北太平洋颱風強度研究提供嶄新的研究方法。除此之外，將延續之前颱風對流不對稱研 究，希望透過閃電資料做為深對流指標的連結，深入探討颱風不對稱結構形成的機制。應用方面， 閃電資料預期能做為颱風快速強度發展與結構特徵的指標，這對台灣民眾所在意的颱風強度及風雨 分布的分析與預測將提供莫大的助益。
Taiwan is located in northwest Pacific where tropical cyclones is active. Each year about 30 typhoons (TCs) generated in this region, 3 to 4 TCs invaded Taiwan per year in average, and provided 60% of the summer rainfall of the island. Taiwan's land area is not large, but it has a complicated and towering terrain. Whenever the TC crossed Taiwan, the TC’s circulation was greatly interacted with the terrain, making forecasting and disaster prevention operations have some difficulty. In the past, it has been found that the vertical wind shear caused the TC to produce asymmetric convective structures, and it caused strong precipitation in the downshear region. However, the TC’s intensity forecast is still a very important and difficult issue to understand. In this couple years, Taiwan was invaded by Typhoon Soudelor (2015), Typhoon Dujuan (2015), Typhoon Nepartak (2016), Typhoon Meranti (2016) and Typhoon Megi (2016), which have moderate intensity category at least. Some of them also appear the scenario of rapid intensification before approached Taiwan. The focus of this research project is to investigate the characteristics of deep convection induced by lightning data on TC intensity development, structure pattern and convection patter during the typhoon-terrain interaction effect. In the academic research, the relationship between inner-core convection outburst and TC’s rapid intensification will be discussed, and this new research method for typhoon intensity in the Northwest Pacific is expected. In addition, the study of TC convection asymmetry will be carried on. It is hoped that the mechanism of the asymmetric structure’s formation will be further discussed through the linking of lightning data as deep convection index. For applications, lightning data are expected to be the indicator of TC development and structure characteristics, which will be of great help to TC’s intensity, rainfall analysis and prediction. |
