ENSO年後春季東亞大氣特性之分析第一部份：海溫及外逸長波輻射特徵

Spring Time East Asia Large Scale Characteristics Post ENSO Part I: The Spatial Distribution of SST and OLR

王作臺(Jough-Tai Wang) ； 胡志文(Jyh-Wen Hwu)

《大氣科學》 22卷3期 (1994/09) Pp. 339-360

摘要

本研究主要是來探討熱帶海溫的變化對東亞地區天氣／氣候變化的可能影響，著重在於瞭解所謂ENSO年後的春季在東亞地區的一些氣象變數和熱帶西太平洋及中太平洋之空間關係。吾人以經驗正交函數（EOF）及奇異值分析方法（SVD）來分析海溫及外逸長波輻射（OLR），來瞭解其特徵向量的空間結構及其所能解釋的整體變異程度。以距平場的值經EOF及SVD之分析，針對ENSO成熟期後的春季做深入的瞭解，有了一些初步的結果。結果顯示，在ENSO成熟期後的春季，赤道中及東太平洋區仍是有較高的海溫及強對流活動，赤道區西太平洋有較低的海溫及較高的OLR，而同時，副熱帶西太平洋之海溫及OLR與熱帶中太平洋之分佈狀況類似，亦即較容易有較高的海溫及稍強之對流活動於副熱帶西太平洋區。本研究是此序列研究之第一部份，第二部份則著重在於瞭解ENSO成熟期後春季環流場之擾動，同時更提出一推論來總結及歸納分析之結果，並將對此推論做一較深入之討論。

關鍵字

梅雨 ； ENSO年 ； 大尺度特徵

並列摘要

This study attempts to identify the effect of the tropical forcing on the weather and climate in the East Asia region. The spatial pattern of certain meteorological variables during the Spring period after the mature phase of ENSO events are the focal points of this investigation.In order to reveal the spatial pattern of the eigen vectors of the sea surface temperature (SST) and the outgoing longwave radiation (OLR), Empirical Orthogonal Function (EOF) analysis, along with the Singular Value Decomposition (SVD) methods are adopted. Some of the preliminary results are presented here.The results indicate, during the Spring time after the mature phase of ENSO, equatorial central and eastern Pacific area have higher SST and lower OLR values, while the SST is lower and OLR values higher in the equatorial western Pacific. And it is also found that the subtropical western Pacific area possesses similar in phase distribution with the equatorial central Pacific area. Namely, it tends to have higher SST and lower OLR values in the subtropical western Pacific area.This study contains two parts. Only part I results are presented in this study. Part II of this study will emphasize in understanding the circulation characteristics during the Spring period, also after the mature phase of ENSO events. A conjecture is also postulated in part II to summarize those essential anomaly patterns. More discussion are provided to further explain this conjecture.

並列關鍵字

Mei-Yu ； Post-ENSO ； Large scale characteristics ； OLR ； SST