This study identifies that cold surges over the South China Sea (SCS) have experienced a significant change on decadal time scales. The results indicate that cold surges occur more frequently after the early 2000s than before and are at least partially explained by changes in circulation patterns. Both the negative phase of the Scandinavian (SCA) pattern and the cold phase of Interdecadal Pacific Oscillation (IPO) can induce increased cold surges and the IPO effect dominates in recent decades. When the IPO shifts to its cold phase, low-level cyclones are induced over the western North Pacific through a Gill response. The northeasterlies along the northwest flank of the cyclones further lead to intensified cold surges over the SCS. The above processes can be reproduced in coupled models, suggesting a robust connection between IPO and cold surges. The present findings highlight the role of tropical forcing and bring an insight into understanding of the future climate variability and change over East Asia during boreal winter.
 

Cold surge,South China Sea,Decadal variability,Coupled models,Pacific decadal oscillation