Impact of global warming on the East Asian winter monsoon as revealed by nine coupled atmosphere-ocean GCMs

Impact of global warming on the East Asian Winter Monsoon (EAWM) is studied using nine coupled atmosphere-ocean general circulation models (AOGCMs). Models are mostly successful in simulating the basic features of the EAWM with varied location of monsoon northwesterlies ( NW). Under the global warming scenario, most models show a weakening of the EAWM accompanied by a strong anticyclonic anomaly over the North Pacific corresponding to a weakened and/or the northern shift of the Aleutian Low (AL). Response in Sea Level Pressure (SLP) also shows the weakening of both the AL and the Siberian High (SH), which gives rise to a weakened pressure gradient along the eastern coast of the Eurasian continent. Among other factors, weakening of the tropical local Hadley circulation was found to substantially weaken the East Asian Jet (EAJ) and the resultant EAWM.