The Variability of the Indian–East Asian Summer Monsoon Interface in Relation to the Spring Seesaw Mode between the Indian Ocean and the Central-Western Pacific

• DOI: 10.1175/jcli-d-15-0839.1
• Publication Date: 2016-04-21T18:37:25Z
• Authors: Jie Cao; Shu Gui; Qin Su; Yali Yang
• Keywords: Westerlies; East Asian Monsoon; Atmospheric Circulation; Walker circulation; BENGAL

Abstract The interannual zonal movement of the interface between Indian summer monsoon and East Asian (IIE), associated with spring sea surface temperature (SST) seesaw mode (SSTSM) over tropical Ocean (TIO) central-western Pacific (TCWP), is studied for period 1979–2008. observational analysis based on Twentieth Century Reanalysis data (version 2) atmospheric circulations, Extended Reconstructed SST 3), Climate Prediction Center Merged Analysis Precipitation. results indicate that IIE’s significantly persistently correlated TIO–TCWP SSTSM, from to summer. two case studies resemble those obtained by regression analysis. Experiments using an general circulation model (ECHAM6) substantiate key physical processes revealed in When warmer (colder) SSTs appear TIO colder (warmer) occur TCWP, positive (negative) SSTSM forces anomalous easterly (westerly) winds Bay Bengal (BOB), South China Sea (SCS), western North (WNP). further result a weakened (strengthened) southwest BOB strengthened (weakened) southeast SCS WNP. This causes IIE shift farther eastward (westward) than normal.