Indian Ocean Dipole Response to Global Warming: A Multi-Member Study with CCSM4  

作　　者：ZHOU Zhen-Qiang XIE Shang-Ping ZHENG Xiao-Tong LIU Qinyu 

机构地区：[1]Physical Oceanography Laboratory and Key Laboratory of Ocean-Atmosphere Interaction and Climate in Universities of Shandong,Ocean University of China [2]Scripps Institution of Oceanography,University of California at San Diego,La Jolla,CA 92093-0230,USA

出　　处：《Journal of Ocean University of China》2013年第2期209-215,共7页中国海洋大学学报（英文版）

基　　金：supported by the National Basic Research Program of China(2012CB955603);the Natural Science Foundation of China(41106010,41176006);the 111 Project(B07036);the Qianren Program

摘　　要：Based on a coupled ocean-atmosphere model, the response of the Indian Ocean Dipole (IOD) mode to global warming is investigated with a six member ensemble of simulations for the period 1850-2100. The model can simulate the IOD features rea-listically, including the east-west dipole pattern and the phase locking in boreal autumn. The ensemble analysis suppresses internal variability and isolates the radiative forced response. In response to increasing greenhouse gases, a weakening of the Walker circula-tion leads to the easterly wind anomalies in the equatorial Indian Ocean and the shoaling thermocline in the eastern equatorial Indian Ocean (EEIO), and sea surface temperature and precipitation changes show an IOD-like pattern in the equatorial Indian Ocean. Al-though the thermocline feedback intensifies with shoaling, the interannual variability of the IOD mode surprisingly weakens under global warming. The zonal wind feedback of IOD is found to weaken as well, due to decreased precipitation in the EEIO. Therefore, the atmospheric feedback decreases much more than the oceanic feedback increases, causing the decreased IOD variance in this model.Based on a coupled ocean atmosphere model, the response of the Indian Ocean Dipole （IOD） mode to global warming is investigated with a six member ensemble of simulations for the period 1850-2100. The model can simulate the IOD features realistically, including the east-west dipole pattern and the phase locking in boreal autumn. The ensemble analysis suppresses internal variability and isolates the radiative forced response. In response to increasing greenhouse gases, a weakening of the Walker circulation leads to the easterly wind anomalies in the equatorial Indian Ocean and the shoaling thermocline in the eastern equatorial Indian Ocean （EEIO）, and sea surface temperature and precipitation changes show an IOD-like pattern in the equatorial Indian Ocean. Although the thermocline feedback intensifies with shoaling, the interannual variability of the IOD mode surprisingly weakens under global warming. The zonal wind feedback of IOD is found to weaken as well, due to decreased precipitation in the EEIO. Therefore, the atmospheric feedback decreases much more than the oceanic feedback increases, causing the decreased IOD variance in this model.

关 键 词：Indian Ocean Dipole （IOD） multi-member ensemble analysis global warming ocean-atmospheric interaction CCSM4 

分 类 号：P732[天文地球—海洋科学]