The Indian Ocean has warmed rapidly and notably at a faster rate than the other tropical ocean basins in the latter half of the twentieth century. We conduct sensitivity experiments using an atmospheric general circulation model to determine the impact of Indian Ocean surface warming on large-scale global atmospheric circulation trends and rainfall distribution, in terms of its pattern and magnitude. Indian Ocean warming drives changes in the local Indian Ocean Walker cell that leads to anomalous easterlies over the Pacific Ocean and strengthens the Pacific Walker Circulation. The anomalous Indian Ocean Walker cell results in anomalous subsidence over Central Africa and the tropical Atlantic, where it is associated with a precipitation decrease over the equator. During austral summer, Indian Ocean warming is associated with the intensification of the northern hemisphere Hadley cell and strengthening of the extratropical atmospheric circulation resembling a positive North Atlantic Oscillation. During austral winter, it is associated with weakening of the southern hemisphere Hadley cell and strengthening of a positive Southern Annular Mode pattern. More intensive warming in the western region of the Indian Ocean basin compared to the east has a significant impact on rainfall trends in the basin, easterly wind trend in the western Pacific and intensity of Hadley circulation changes. It is, however, the Indian Ocean warming across the entire basin that dominates the drying of the tropical Atlantic and the trends in extratropical modes of variability. This study suggests the Indian Ocean warming could have potentially influenced global atmospheric circulation trends observed in the recent decades.

在20世纪下半叶，印度洋的变暖速度比其他热带海盆迅速，而且变暖速度明显更快。我们使用大气总循环模型进行敏感性实验，以确定印度洋表面变暖对全球全球大气环流趋势和降雨分布的影响，包括其模式和强度。印度洋的变暖推动了当地印度洋沃克单元的变化，从而导致太平洋上的东风异常并加强了太平洋沃克环流。印度洋Walker单元的异常导致中非和热带大西洋上的异常沉降，这与赤道上方的降水减少有关。在南方的夏季，印度洋的变暖与北半球Hadley细胞的增强和类似北大西洋涛动的温带大气环流的增强有关。在南方冬季，它与南半球Hadley细胞的减弱和正南环模模式的增强有关。与东部相比，印度洋盆地西部地区的变暖强度更大，对盆地的降雨趋势，西太平洋的东风趋势以及哈德利环流变化的强度有重大影响。但是，整个洋盆的印度洋变暖是热带大西洋干燥和温带变率模式趋势的主导。