基于IPCC A1B情景的中国未来气候变化预估:多模式集合结果及其不确定性

Projected Climate Change over China Under SRES A1B Scenario:Multi-model Ensemble and Uncertainties

利用耦合模式比较计划(CMIP3)提供的20世纪气候模拟试验(20C3M)及A1B情景预估试验,讨论了全球增暖情景下21世纪中期中国气候的可能变化。结果表明,A1B情景下,中国夏季降水变化在-0.1～1.1mm/d,冬季降水变化在-0.2～0.2mm/d。模式对降水变化的预估存在较大不确定性。无论冬夏,预估的全国表面气温都将升高,升温幅度在1.2～2.8℃;随纬度升高,增暖幅度相应增大。模式对表面气温变化的预估能力强于对降水变化的预估能力。在A1B情景下,东亚夏季风增强,而冬季风则略为减弱,东亚夏季风雨带到达最北后南撤的时间较之20C3M滞后约一个月。

Climate change over China in the middle 21st century is investigated based on the multi-model datasets of 20C3M and the SRES A1B scenario projection provided by CMIP3.The analysis shows that the precipitation will increase in most parts of China;the range of rainfall change is between-0.1 and 1.1 mm/d in summer,and between-0.2 and 0.2 mm/d in winter.Unfortunately,our analysis has revealed a large spread among the 23 models in future precipitation change projection.Uncertainties in the surface air temperature（TAS） change projection are far less than those in precipitation.The projected change range of TAS,in both summer and winter,is from 1.2 to 2.8℃,generally increasing with latitude.Projected change of East Asian monsoon under the SRES A1B scenario exhibits a strengthened trend in summer but a slightly weakened trend in winter;and the withdrawal of the East Asian summer monsoon rain-belt from its north-most position is about one month later than that in 20C3M.