On the association between spring Arctic sea ice concentration and Chinese summer rainfall

A statistical relationship between spring Arctic sea ice concentration (SIC) and Chinese summer rainfall is identified using singular value decomposition (SVD). Results show that decreased (increased) spring SIC in the Arctic Ocean and the Greenland Sea corresponds to increased (decreased) summer rainfall in northeast China and central China between the Yangtze River and the Yellow River (28° 36°N); and decreased (increased) rainfall in south China. Corresponding summer 500 hPa height anomalies show a Eurasian wave train structure, which originates in northern Europe and extends southeastwards to northeast China, and a south-north dipole structure over East Asia south to Lake Baikal. Such a spatial distribution of 500 hPa height anomalies and corresponding summer rainfall anomalies cannot be entirely attributed to the impact of East Asian summer monsoon (EASM) variability. The spring Arctic SIC provides a complementary precursor for Chinese summer rainfall variability. The combined impacts of both spring Arctic SIC and Eurasian snow cover on the Eurasian wave train may explain their statistical linkage.