Global Warming Projection by an Atmospheric Global Model with 20-km Grid

Abstract

We projected global warming on the Earth Simulator using a very high horizontal resolution atmospheric global general circulation model with 20-km grids, targeting tropical cyclones (TCs) and the rain band (Baiu) during the East Asian summer monsoon season because these bring typical extreme events and global climate models have not yielded reliable simulations or projections due to insufficient resolutions. Our model reproduces TCs and a Baiu rain band reasonably well under present-day climate conditions. In a warmer climate at the end of this century, the model projects, under A1B scenario of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES), that the annual mean formation frequency of TCs decreases by about 30% globally but increased in the North Atlantic and TCs with largemaximumsurface winds increase. The Baiu rain band activity tends to intensify and last longer until August, suggesting more damages due to heavy rainfalls in a warmer climate. This is a review paper mainly originated from published articles on tropical cyclone by Oouchi et al. (2006) [26] and on the East Asian summer monsoon by Kusunoki et al. (2006) [17].