北极涛动的年代际变化及其气候影响

Interdecadal variation of the Arctic Oscillation and its influence on climate

摘要:

北极涛动（Arctic Oscillation，AO）是北半球热带外地区大气环流变率的主导模态，对北半球以及区域尺度气温变化具有重要影响。AO可在没有外强迫条件下通过波流相互作用形成，因此它被认为是全球气候系统内部变率的重要组成部分。研究年代际尺度上AO的变化及其气候影响，可加深对当前北半球气候变化规律的物理理解，也可为预估未来年代际尺度上气候变化及其不确定性提供科学依据。本文从AO影响东亚冬季风年代际变化的物理机制、AO对北半球冬季气温长期趋势的贡献、AO年代际影响的不确定性三个方面出发，简要回顾和总结了近年来有关年代际尺度上冬季AO时空变化及其对北半球气候影响的研究成果，并初步展望一些值得继续深入研究的问题。

关键词:北极涛动;行星波;年代际变化;内部变率;气候变化

Abstract:

The Arctic Oscillation (AO) is the dominant mode of atmospheric circulation in the extratropical Northern Hemisphere,which exerts widespread influences on the Northern Hemispheric and regional temperature changes.AO can be generated via wave-mean flow interactions without the presence of atmospheric external forcing.Hence,it is considered to be an essential component of the internal variability of the global climate system.Investigating the interdecadal variation of the AO and its impacts on climate helps to deepen the physical understanding of the observed climate change and variability in the Northern Hemisphere.Meanwhile,it also provides a scientific basis for the near-term projection of climate change and its uncertainty on the interdecadal scale.This paper briefly reviews and summarizes the recent research on the temporal and spatial variations of wintertime AO on the interdecadal scale and their impacts on the climate in the Northern Hemisphere.Three aspects are reviewed,including the physical mechanism of influences of the AO on interdecadal variations of the East Asian winter monsoon,the contribution of the AO to long-term trend of wintertime air temperature in the Northern Hemisphere,and the uncertainty of interdecadal influence of the AO.The possible issues that deserve future research are also discussed.

Key words:Arctic Oscillation;planetary wave;interdecadal variation;internal variability;climate change