抄録
Future climate change around Japan was projected with a non-hydrostatic regional climate model with a 5-km grid spacing. The future surface air temperature, averaged over all of Japan, is projected at the 99% confidence level to rise about 3°C in each month of the year. Diurnal temperature ranges are projected to increase in many areas, especially over plains on the Pacific Ocean side in February, as the warming rates of minimum temperatures are small as compare to other areas. This is due to that minimum soil temperatures of just below 0°C occur with high frequency in both the present and future climates, because they are constrained by the heat of solidification. Storm tracks are projected to approach the Japan Archipelago in February, leading to a remarkable increase in precipitation along the Pacific coast of Japan. The annual occurrence frequency of heavy precipitation is also projected to increase. The maximum snow depth is projected to decrease almost everywhere, but the changes will be small in high mountains and in northern Japan.
