Influence of interannual variability of Antarctic oscillation on mei-yu along the Yangtze and Huaihe River valley and its importance to prediction

Abstract

Both correlation analysis and case study indi- cate that Antarctic oscillation (AAO) is closely related with summer rainfall in eastern China. When AAO is stronger in boreal spring, especially in May, there is more mei-yu rain- fall in summer with a longer period along the Yangtze and Huaihe River valley. In contrast, there is less rainfall with a shorter period corresponding to a weaker AAO. Besides, an anomalous AAO changes the position and intensity of several circulation systems, which are important to summer rainfall along the Yangtze and Huaihe River valley. Furthermore, the Antarctic sea ice is negatively correlated with the intensity of AAO with a 6-month leading time. The result in this study provides a new method for the prediction of mei-yu.