台灣梅雨季降水之年降變化

The Interannual Variability of Taiwan's Mei-Yu

吳明進(Ming-Chin Wu) ； 傅達颺(Ta-Yaung Fu)

《大氣科學》 15卷1期 (1987/03) Pp. 31-42

摘要

用經驗正交函數展開、分區降水指數計算、隨機檢定、無趨勢測驗、相關分析和波譜分析等統計方法分析台灣地區20個氣象局所屬雨量站1950－85年月降水資料。結果顯示：台灣地區影響梅雨季降水之主要因素為地形、南北緯度、和中央山脈阻隔；影響台灣年降水分佈之主要因素則為地形、季風、和東南－西北走向的系統；梅雨季的潮濕或乾燥在空間的南北分佈有相當的一致性，而時間的前後期則差異較大；梅雨季降水的年際變化大體上是隨機分佈和無長期趨勢；梅雨季降水的週期除六月之準兩年期及9年期振盪外並不明顯。

並列摘要

Applying empirical orthogonal function (EOF) analysis, area rainfall index computation, randomness test, non-trending test, correlation analysis, and spectral analysis to examine 1950-1985 monthly rainfall records of 20 Central Weather Bureau's surface stations. The following conclusions reached. The main factors causing the vagaries of the Taiwan's Mei-Yu rainfall are the topography, the latitude , and the blocking of the Central Mountain Range; The main factors causing the vagaries of the annual rainfall are the topography, the monsoons, and the atmospheric regimes oriented in the Southeast and Northwest; wet and dry years of the Mei-Yu appear to be quite coherence in the North-South spatial distribution, but quite different in the early-late stages of the season; area rainfall of the Mei-Yu season is almost random distributed in time and without long-term trend; the periodicity is no t significant except the quasi-biennial and 9 years oscillations for June.