Abstract
Regional climate in East Asia under 1CO2 and 2CO2 conditions was simulated for continuous 10-year periods by the RegCM2.5 developed by NCAR, using the output of a CO2 transient run from NCAR-CSM as lateral and surface boundary conditions. The typical winter precipitation events on the northwestern side of Japan (Japan Sea side) caused by the monsoons and the precipitation in and around Japan caused by the Bai-u front (Meiyu front) in June were reproduced realistically by the RegCM with a horizontal resolution of 50km. With doubling of the concentration of CO2, air temperature typically increases in the northern region in winter. The precipitation increases on and around the Bai-u front (by 20 to 30%) are significant at the 5%(partly 1%) level. However, the location of the Bai-u front does not shift from 1CO2 climate to 2CO2 climate or slightly shifts to the north. In the typical four climate districts in Japan, the biases and the change of the surface air temperature and the precipitation are analyzed and discussed.
