不同温室气体排放情景下中国21世纪地面气温和降水变化的模拟分析

Changes of Surface Air Temperature and Precipitation in China during the 21st Century Simulated by HadCM2 under Different Greenhouse Gas Emission Scenarios

利用HadCM2模式的模拟结果 ,比较了温室气体排放综合效果相当于CO2 浓度逐年递增 1 %和 0 5 %两种不同情景下 ,中国区域 2 1世纪地面气温和降水量的变化趋势。结果表明 ,随着温室气体浓度的持续增加 ,中国地面气温也持续升高。到 2 1世纪末期 ,地面气温在上述两种排放情景下可分别升高约 5℃和 3℃。两种排放情景的增温趋势对比表明 :即使从 1 990年开始温室气体等效排放逐年递增率减少一半 ,增温仍然很明显 ;直到 2 1世纪中期 ,才能显示出减少温室气体排放量对减缓增温趋势的效果。降水量的年际变化较大 ,但随着温室气体浓度的持续增加 ,降水量总的趋势也是增加的。减排温室气体对降水量变化趋势的影响与地面气温相似。此外 ,地面气温增量和降水量变化百分率均显示出明显的季节变化 ,地面气温增量在秋、冬季较大而在春、夏季较小 ,降水变化百分率在夏、秋季较小而在冬。

Based on the results simulated by HadCM2 under two greenhouse gases emission scenarios, in which equivalent CO 2 increases respectively by 1% and 0 5% per year in concentration since 1990 onward, changes of surface air temperature and precipitation in China during the 21st century are compared. It is shown that the surface air temperature in China rises gradually due to continuous increase of equivalent CO 2 in concentration. By the end of the 21st century, the surface air temperature increases by ～5 ℃ and ～3 ℃ under the two scenarios respectively. The temperature increment of time series further shows that the surface air temperature tends to rise obviously even if equivalent CO 2 increases by 0 5% per year in concentration since 1990. The temperature increment under 0 5% scenario cannot be diminished obviously relative to 1% scenario until the middle 21st century. Through with larger interannual variability, the precipitation also tends to increase with greenhouse gases emission increasing. In addition, the effect of greenhouse gas reduction on precipitation is similar to that on surface air temperature. Furthermore, both temperature increment and percentage of precipitation increment dipict a clear annual cycle, the surface air temperature increments during autumn and winter are larger than those during spring and summer, however, the percentage of precipitation increments is larger during winter and spring than during summer and autumn.