臺灣降水變化及其季節性異常的環流機制

Relationship between Precipitation in Taiwan and Atmospheric Circulation over East Asia

朱錦紅(Jin-Hong Zhu) ； 柯文雄(Wen-Shung Kau) ； 許晃雄(Huang-Hsung Hsu)

《環境保護》 27卷1期 (2004/06) Pp. 72-89

https://doi.org/10.30017/EP.200406.0005

摘要

利用臺灣降水資料、NINO3.4區海溫、500hPa高度場和海平面氣壓以及登陸臺灣颱風數對臺灣不同時期降水變化以及與此相聯繫的東亞大氣環流做了分析，並研究了近百年降水的變化。結果顯示，在不同季節，影響臺灣降水的大尺度大氣環流系統不同，副高、季風、颱風分別在不同季度起到重要作用。EOF分析顯示，臺灣年和㈪的降水空間變化㆒致的特點十分顯著。雖然在各個季節解釋方差不同，但EOF1都超過42.9%，而且其空間特徵隨季節變化不大。EOF2顯示臺灣複雜的地形對降水分佈有明顯影響。從近百年降水變化看，年總降水量和各季節降水量的年際和年代際變化顯著，但沒有明顯的趨勢變化。各季降水長期變化特點，與這一季節影響臺灣降水的主要環流系統的長期變化特徵有密切關係。

關鍵字

臺灣降水 ； 東亞大氣環流 ； NINO3.4海溫

並列摘要

The characteristic of precipitation in Taiwan is studied based on rain gauge data set for 1969-2000. Empirical Orthogonal Function (EOF) analysis indicates that consistent variations of annual and monthly precipitation are predominant in the whole domain. The variances explained by the first modes are more than 42.9% for either annual or monthly precipitation. EOF2 describes that variations of precipitation over east of Central Mountain are opposite to those over west of Central Mountain. It illustrates that the impact of terrain on distribution of precipitation is obvious. Relationships between rainfall over Taiwan and atmospheric circulation over East Asia and sea surface temperature (SST) over NINO3.4 are analyzed based on rain gauge data set in Taiwan, geopotential height at 500hPa level, amount of typhoon landed Taiwan and sea level pressure (SLP) for the period of 1901-1999. It shows that subtropical high over western Pacific, Asian Monsoon, typhoon and NINO3.4 SST are related closely to rainfall in Taiwan during different seasons. The interannual and interdecadal variability of precipitation, atmospheric circulation over East Asia and NINO3.4 SST exist but no trend is found. The variation of precipitation is highly related to atmospheric circulation and SST over NINO3.4 during the past 100 years.

並列關鍵字

Precipitation in Taiwan ； Atmospheric Circulation ； NINO3.4 SST