东亚和西北太平洋地区气候的准10年尺度振荡及其可能机制

Quasi-Decadal Oscillation of Climate in East Asia/Northwestern Pacific Region and Possible Mechanism

本文基于对气候、大气环流和海表水温的资料分析以及简单的理想化海气耦合模式的分析，研究了东亚和西北太平洋地区气候的准１０年振荡及其可能机制。研究表明，东亚和西北太平洋地区的气候（降水和地面气温等）和大气环流（环流指数和副高活动等）的演变都有明显的准１０年振荡；同赤道太平洋ＳＳＴＡ主要为ＥＮＳＯ循环不同，西北太平洋ＳＳＴＡ主要表现为准１０年尺度的振荡，且同气候和大气环流的准１０年变化密切相关；中纬度海－气相互作用可产生一种甚低频耦合波（１０年左右周期）。

Based on the data analyses in climate, atmospheric circulation and sea surface temperature (SST) and the theoretic analysis in a simple air-sea coupled model, the quasi-decadal oscillation of the climate in East Asia/Northwestern Pacific and the possible mechanism are studied. The results show that the evolutions of climate (precipitation and temperature) and atmospheric circulation (circulation index and the activity of subtropic high) in East Asia/Northwestern Pacific region all have clear quasi-decadal oscillation. The SSTA in the northwestern Pacific also shows quasi-decadal oscillation, differing from SSTA in the equatorial Pacific which shows the ENSO cycle mainly, and this oscillation associates with quasi-decadal variation of climate and atmospheric circulation. The air-sea coupled interaction in the middle latitude can excite a very low-frequency mode (about 10 years period) and it is a possible mechanism to drive quasi-decadal oscillation of the air-sea system in the middle latitude.