Mysterious post-El Nino effect on the Asian summer monsoon
|対象||教職員向け 大学院生向け 学部生向け|
|イベント概要||講演者：Prof. Xie ShangPing （カリフォルニア大学サンディエゴ校 スクリプス海洋研究所）
要旨：El Nino’s contemporaneous effect on India summer rainfall is well known and led to the discovery of the Southern Oscillation nearly 100 years ago. More recent studies revealed widespread correlations of summer rainfall over India and eastern China with the antecedent El Nino-Southern Oscillation (ENSO). This is peculiar because ENSO peaks in boreal winter and decays rapidly in the following spring. In fact, summer sea surface temperatures (SSTs) of the equatorial Pacific are not correlated with the antecedent ENSO.
We review the recent advances in unraveling this mystery that led to the discovery of the Indo-western Pacific ocean capacitor (IPOC), a regional coupled mode of wind-evaporation-SST (WES) feedback between an anomalous anticyclonic circulation and SSTs over the Indo-Northwest Pacific region. Being the least damped mode, the IPOC brings about predictability and shapes ocean-atmospheric anomalies in post-El Nino summer. We will discuss ongoing research addressing important questions of what shapes the preferred patterns of Asian summer monsoon variability and how to track this variability.