Change in future tropical cyclone activity over the western North Pacific under global warming scenario

Differences in atmospheric and oceanic environments which affect the tropical cyclone (TC) activity between the late twenty-first century (2071-2100, A1B) and the late twentieth century (1971-2000, 20C3M) are analyzed using multi-model ensemble from 15 general circulation models. Six factors (vertical wind shear, 700 hPa relative humidity, 850 hPa relative vorticity, outgoing longwave radiation, precipitation, and sea surface temperature) related to TC genesis predicts that more TCs in the future will occur than in the present. The result of maximum potential intensity analysis shows the frequency of occurrence and influence of stronger TCs will increase over the western North Pacific in the future. Anomalous northerly in the mid-latitudes of East Asia due to the strengthening of west-high and east-low pressure system pattern in the future plays an important role in blocking TC from moving toward mid-latitudes of East Asia. The multiple linear regression model (MLRM) developed using six predictors (independent variables) analyzed from NCEP-NCAR reanalysis data predicts that total TC genesis frequency during July to October (JASO), which predicted using data of 20C3M, will have more (2-3) TCs than in the present.