基于全球模式对中国21世纪夏季高温的变化预估

EVALUATING THE SIMULATION BY GCMS OF SUMMER HIGH-TEMPERATURES IN CHINA

根据12个全球气候系统模式(GCM)3种排放情景(A2,A1B和B1)下对中国地区21世纪近100 a的夏季平均气温的模拟值,以1971—2000年为基准,计算并分析了该区域未来夏季高温的变化趋势.不同排放情景下各模式的模拟结果不同,且各模式对夏季高温模拟的差异大于对异常高温的模拟.就模式平均而言,A2情景下高温日数最多,A1B次之,B1情景下最少.增长趋势也是A2情景下最快为6.0 d.(100 a)-1,A1B和B1情景分别为5.4和3.4 d.(100 a)-1.对异常高温频次的模拟,B1情景下异常高温频次最多,为8.8 d.a-1,A1B和A2情景下均为8.7 d.a-1,三者之间差距很小.A2情景下异常高温频次增长最快,增长趋势为2.6 d.(100 a)-1,A1B情景下增长略慢,为1.9 d.(100 a)-1,B1情景下增长最慢,仅为1.5 d.(100 a)-1.对3种情景下各模式对高温日数的模拟能力进行了分析,从多方面比较了各模式的模拟能力.

Based on summer max temperature data during 1971 - 2000 in China and the simulation value of summer temperature under the SRES A2, AIB and B1 scenarios in the 21st century of 12 GCMs supplied by the IPCC-AR4, The trend of summer high-temperature changes in China in 21st century has been evaluated. The simulation of GCMs under three SRES is different, and the simulation difference of high temperature days is greater than abnormal high frequency. The trend of results of HADCM3 and MPEH5 are consistent with average results of all models. For the model average results, high temperature days under SERS A2 scenario are more than other scenarios. The increasing trend （6.0 d/（100 a）） under SERS A2 scenarios is fastest in three scenarios; the increasing trend under SRES AIB and B1 scenarios is 5.4 and 3.4 d/（100 a） respectively. Compared with the early 21 century, max temperature and number of high temperature days increase in late 21 century. The change ranges under the three scenarios are different, but variability is almost the same （10. 4- 10. 5 d/℃）. The simulation of abnormal high frequency under SERS A2 scenario, 8. 8 d/a, is more than other scenarios, 8. 7 d/a, and the difference is extremely small from each other. The increasing trend（2.6 d/（100 a）） under SERS A2 scenarios is fastest in three scenarios; the increasing trends under SRES A1B and B1 scenarios are 1.9 d/（100 a） and 1.5 d/（100 a） respectively.