CLIMATE CHANGE DUE TO GREENHOUSE EFFECTS IN CHINA AS SIMULATED BY A REGIONAL CLIMATE MODEL—PART Ⅱ:CLIMATE CHANGE^*

Impacts of greenhouse effects(2×CO2) on climate change over China as simulated by a regional climate model have been investigated.The model was based on RegCM2 and is nested in one-way mode within a global coupled atmosphere-ocean model(CSIRO R21L9 AOGCM).Two multi-year simulations,the control run with normal CO2 concentration and sensitivity run with doubled CO2 concentration are conducted. As Part II of the publications,with a brief analysis of the 2×CO2 experiment by CSIRO R21Lg,results of the 2×CO2 simulation by RegCM2 are analyzed in detail. Results of the RegCM show a remarkably warming over China with an increment ranging from 2.2℃ in southern China to 2.8℃ in northern due to greenhouse effect.The regional averaged annual temperature increase is 2.5℃.The warming is greater in winter and spring.Daily maximum and minimum temperatures increase also over China which lead to much more hot spell days in summer and less cold spell days in winter. Precipitation increases in all seasons of the year,with the greatest found in summer.Annual mean precipitation increases significantly in western China,parts of the area in south of the Yangtze River and northern part of the Northeast.while a decrease in the area from southern part of the Northeast to North China is simulated.The regional averaged annual increase of precipitation is 12%.More heavy rain events are found noticeably in southern China.The simulated tropical storms affecting and landing over China tend to increase.Analysis on the simulation of circulation pattern showed that the 500 hPa height in East Asia might rise significantly.