Relationship between the Modes of Winter Tropical Pacific SST Anomalies and the Intraseasonal Variations of the Following Summer Rainfall Anomalies in China

In present study, EOF analysis and extended singular value decomposition (ESVD) analysis are performed to explore the relationship between the winter tropical sea surface temperature anomalies (SSTAs) in the Pacific and the following summer rainfall anomalies in China. The two leading modes of winter tropical SSTAs in the Pacific are the SSTAs pattern characterized by "positive anomalies in the East and negative anomalies in the West" like the typical eastern Pacific El Nino and negative anomalies in the West and the central Pacific warming pattern characterized by "positive anomalies in the central region but negative anomalies in the East and West". The intraseasonal variations of the rainfall anomalies during the following summer in China that are associated with the eastern Pacific warming mode are characterized by positive anomalies south of the Yangtze River and negative anomalies in the Yangtze-Huai River Valley in June, and negative anomalies in South China and positive anomalies in the Yangtze River Valley and North China in July and August. In contrast, after the central Pacific warming mode, the corresponding intraseasonal variations of China's summer rainfall are characterized by a nearly consistent pattern during the three summer months, which is positive in the South China coast and North China and negative in the Yangtze River Valley except for the positive anomalies in the Yangtze-Huai River Valley in July. These results may provide a reference for the seasonal prediction of the summer drought and flood distributions in China.