Influence of the boreal spring Southern Annular Mode on summer surface air temperature over northeast China

Abstract

Previous evidence has showed that the boreal spring Southern Annular Mode (SAM) regulates summer monsoon precipitation in East Asian subtropics through the Northern Indian Ocean sea surface temperature (NIO SST). This paper further demonstrates how a positive (negative) boreal spring SAM is usually followed by a warmer (cooler) summer over northeast China (NEC), suggesting impacts of the SAM even extend to the northern mid-latitudes. A positive spring SAM usually leads to anomalous anticyclonic sinking motion over NEC during summer through the NIO SST, which results in cloud reduction and changes in radiation, and thus surface warming.