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 mufti-year simulations, the control run with normal CO2 concentration and sensitive run with doubled CO2 concentration are conducted. As Part Ⅱ of the publications, results of the sensitive runs are analyzed in the paper. With a brief analysis of the sensitive experiment by CSIRO R21L9,simulation by RegCM2 are analyzed in detail. Results of RegCM2 show a remarkably warming over China with a range from 2.2℃ in southern China to 2.8℃ in northern China due to greenhouse effect. The annual area mean temperature increase is 2.5℃.The greatest warming is simulated in winter season by the model. Daily maximum and minimum temperatures increase also over China, which leads 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 highest value found in summer. Annual mean precipitation increases significantly in western China, parts of the area in south of the Yangtz River and northern part of Northeast China,while a decrease in the area from southern part of Northeast China to North China is simulated. The annual area averaged increase is 12%.As for the operational short-term climate prediction for flood season precipitation in China, frequency of "the third type of rain pattern" might increase. Number of heavy rain days is found noticeably increasing in South China. Tropical storms affecting and landing over China tend to increase due to greenhouse effects. Analysis on the simulation of circulation pattern shows that due to the greenhouse effect, the 500 hPa height in East Asia might increase significantly.