地形對雙颱風運動之影響

On the Topographic Effect of Binary Typhoon Systems

劉廣英(Koung-Ying Liu) ； 俞川心(Shuan-Shin Yu)

《大氣科學》 12卷1期 (1985/03) Pp. 81-91

摘要

本文就1960～1984年共25年間，選擇49對在同一時間內分別處在西北太平洋與南海，即在台灣至菲律賓東、西兩側之颱風，分析其相對運動，以探討上述地形對雙颱風相對運動之影響。結果發現，此類雙颱風在地形影響下仍有順轉及逆轉情形發生，但其相對運動之角度變化較西北太平洋上之雙颱風小得很多。除此以外，在上述地形作用下，雙颱風中心相對運動會發生移速、旋轉方向的突然變化，而且上述地形對颱風間牽引作用有阻擋作用，故只有當兩颱風中心連線恰可通過巴士海峽或台灣北部外海時，方會由南海或地形西方移到西北太平洋上，或者自地形東方移到地形西側。文中不但詳列各項統計資料，分析運動特徵，並做個案分析，以顯示地形在雙颱風交互運動中的重要性。

並列摘要

In a previous study one of these authors (Liu, 1983) found the topography was one of the very important factors which influence the relative motion of the binary typhoons. In this study 49 binary systems are selected from the typhoons which occured in the period of 1960 to 1960 and the two centres were, in all or in a certain part of their tracks, separated by Taiwan and Philippines. The results of our analysis and study show that: (1) the relative angular displacements are comparatively smaller than those occurred in the cases without topographic effect; (2) topographic effect makes the relative motion changed abruptly both in direction and in speed; (3) typhoons in South China Sea which interact with a typhoon over NW Pacific Ocean move to the Pacific through Bashi Channel only.Statistical tables, relative tracks and case studies are all presented in this paper. They give the concise look of our work.