2011-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/702285摘要：本計畫第一部份關於颱風結構、強度變化；我們以雙眼牆颱風為切入點，探討颱風眼周圍線性與非線性動力，並旁及對流雨帶以及和渦旋動力的交互作用。我們擬釐清渦旋羅士陪波（線性動力），颱風與周圍大面積不對稱結構的交互作用（非線性動力），在颱風結構與強度變化的角色。除了以數值模擬外，我們將以微波衛星資料探討西北太平洋雙眼牆颱風特性，瞭解雙眼牆颱風的強度變化；此外我們將利用TCS-08計畫中的P-3 飛機觀測資料，分析六個不同發展階段的颱風個案，瞭解對流尺度與渦旋尺度的交互作用，颱風周圍帶狀化機制。第二部份關於臺灣颱風降雨，我們從過去30年的侵台颱風發現，在花蓮以北登陸的颱風若移速緩慢，會給臺灣西南部帶來顯著降雨。我們認為此類型颱風因移動較慢而產生較多的降雨，而旺盛的對流產生的位渦，會對西北行的颱風運動產生延遲的效果；我們假設被地形鎖定的對流降雨會減慢颱風的運動，而颱風減慢又產生更多降雨，成一正回饋關係。我們擬以WRF模式數值實驗配合位渦趨勢診斷方法，來分析動力與降雨影響運動的因素。 2009年莫拉克颱風與2010年梅姬颱風顯示，颱風與冬、夏季風的交互作用對台灣極端降雨有重要影響，而且颱風與季風的交互作用，有明顯年代際關係，我們將探討過去50年颱風強降雨之年代際變化，並將此颱風降雨和季風、颱風運動、地形以及中尺度對流等因素結合，釐清颱風極端降雨多尺度特性。<br> Abstract: We propose to study the convection and vorticity dynamics in the tropical cyclone (TC) environment that may lead to the rapid variability in structure and the intensity of TCs. In particular, we want to differentiate the linear dynamics and the nonlinear dynamics in the concentric eyewall (CE) typhoon dynamics. In addition, we will investigate 6 flights of aircraft radar data for 6 different intensity typhoon cases from TCS08 field experiment. We will also design an objective method to identify the CE typhoons in the microwave satellite data for in Western North Pacific, and to study the structure and intensity change of CE typhoons. The second portion of the proposal is to study the extreme rainfall in Taiwan. We found from the 30 years of data that the amount of typhoon rainfall in Taiwan was nearly proportional to the reciprocal of TC translation speed, rather than the TC intensity. Since the precipitation is often phased locked with terrain, it is possible that convection induced potential vorticity tendency may slow down the typhoon motion. We will use WRF simulations with Potential vorticity tendency diagnostic analysis to study the interaction of terrain, convections and typhoon motion. As examples of Typhoons Morakot (2009) and Megi (2010), the extreme rainfall event is also contributed with typhoon interaction with summer and winter monsoons. The interaction has significant decadal signature. We will analyze the decadal variability of strong typhoon precipitation with a multiple scale approach, which involve the interaction of monsoon, terrain, typhoon motion, and mesoscale convections.雙眼牆線性動力與非線性動力位渦趨勢診斷颱風與季風的交互作用年代際變化concentric eyewalllinear and nonlinear dynamicsPotential vorticity tendency diagnostic analysistyphoon interaction with monsoonsdecadal variability