摘要: | 2015年及2016年共有4個路徑、結構相似,但是不同強度的颱風登陸台灣,不過風雨表現的狀況並非跟颱風強度呈現正相關,因此讓我們想要探討除了強度之外的因素對台灣風雨的影響。
Merrill and Gray (1983)及Weatherford and Gray (1988)均曾提出颱風壯度(Strength)的概念,另外包括Chan and Chan (2012)等人利用衛星觀測資料分析颱風強度、壯度與大小之間變化的相關性。本研究利用NCEP-GFS及CFSR的模式分析資料計算颱風的壯度及大小,發現颱風壯度跟大小之間有良好的正相關性,颱風強度跟壯度、大小之間的相關性較差。三個因素之間有不同的變化情況,包括三者變化一致、強度巔峰過後壯度跟大小仍持續增加以及颱風大小最大值出現在強度巔峰之前等三種類型。
過去的研究發現颱風對台灣風雨的影響因素包括颱風路徑、結構、速度及綜觀環境等,本研究則著重於探討颱風強度、壯度與大小跟台灣風雨的關係。針對台灣整體風雨的分析結果發現颱風壯度及大小跟風雨指標之間的相關性較好,跟強度的相關性較低。針對不同路徑的分析則發現,第二類路徑颱風的強度跟風雨指標相關性較好,風力指標尤其明顯,第三類路徑颱風的大小跟風雨指標的相關性較好,雨量指標尤其明顯。針對不同測站在不同路徑下的分析結果發現,接近颱風內核區的測站風雨指標跟颱風強度的相關性較好,位於颱風外圍區域的測站其風雨指標跟颱風大小的相關性較好。
颱風的壯度及大小對台灣風雨的發生有相當程度的影響,即使是強度較弱的颱風,也可能因為具有較大的壯度或大小而引發大範圍的強風大雨,因此在防災作業上除了颱風強度外,颱風的壯度及大小也應該一併列入考量。
There are four typhoons landed in Taiwan in 2015 and 2016, they have similar paths, structures and different intensity. The situation of wind and rain is not positively related to typhoon intensity, so let us want to explore factors other than strength.
Merrill and Gray (1983) and Weatherford and Gray (1988) have proposed the concept of typhoon strength, Chan and Chan (2012) and others using satellite observations to analyze the correlation changes in typhoon intensity, strength and size. In this study, we use the NCEP-GFS and CFSR model analysis data to calculate strength and size of typhoon. It was found that the typhoon strength had a positive correlation with the size, and the correlation between the typhoon intensity and size, intensity and strength was poor. There are three different types of changes between the three factors, including the three factors changes in the same, intensity after the peak but strength and size continues to increase and the maximum size of the typhoon appeared before the intensity of the peak.
In the past studies, the influence factors of typhoon on Taiwan's wind and rainfall were analyzed, including typhoon path, structure, speed and environment. This study focused on the relationship between typhoon strength, size and Taiwan wind and rainfall. According to the analysis of the overall wind and rainfall in Taiwan, it is found that the correlation between typhoon strength, size and wind, rainfall index is better than typhoon intensity. According to the analysis of different paths, it is found that the intensity of the typhoon of the second type have better correlation in wind and rain index, and the wind index is especially obvious. The correlation between the typhoon size of the third type and wind, rainfall index is better than typhoon intensity, especially the rainfall index is obvious. According to the analysis results of different stations under different paths, it is found that the wind and rain index of the station near the storm core area have better correlated with the typhoon intensity, and the wind and rain index of station over outer-core area of storm have better correlated with the typhoon size. |