CMIP5多模式集合对东北三省未来气候变化的预估研究

Projection of future changes in climate in Northeast China using a CMIP5 multi-model ensemble

应用CN05观测资料,以及参与国际耦合模式比较计划第5阶段(CMIP5)中的26个模式,评估了新一代全球气候模式对东北三省气候变化模拟能力并选出4个较优模式,发现经过筛选得出的较优模式集合平均模拟结果的可靠性得到进一步加强,尤其体现在对气温的模拟上.在此基础上着重分析了多模式集合在不同典型浓度路径(RCPs)下对未来气候变化特征的预估.结果表明:21世纪的未来阶段,东北三省将处于显著增温的状态,且RCP8.5情景下的增温速率(0.53℃/10a)明显高于RCP4.5情景下的速率(0.22℃/10a);空间上,北部地区将成为增温幅度最大、增温速率最高的区域.未来降水将会相对增加,但波动较大,21世纪末期RCP4.5和RCP8.5情景下的降水增加幅度分别为11.24%和15.95%;空间上,辽宁省西部地区将成为降水增加最为显著的区域.根据水分盈亏量,21世纪未来阶段,RCP4.5情景下的东北三省绝大多数地区未来将相对变湿,尤其到了中后期;RCP8.5情景下则是中西部地区将相对变干,其余地区则会相对变湿.

Based on observational data of CN05 and the outputs of 26CMIP5（Coupled Model Inter-comparison Project Phase 5）models adopted in the Fifth Assessment of the Intergovernmental Panel on Climate Change（IPCC AR5）,the abilities of the 26CMIP5 models to simulate surface air temperature and precipitation of the three provinces in Northeast China during 1961—2005were assessed.Four best-fit models were selected by Taylor Diagram out of the 26 CMIP5 models,and simulations of future changes in climate and associated uncertainties under different representative concentration pathways（RCPs）by the multi-model ensemble mean（MME）of the four models were examined.The MME of the four best-fit CMIP5 models has higher credibility to simulate the climate change in Northeast China,especially for surface air temperature.Based on estimates of water deficit,future climatological drought in Northeast China was analyzed under RCP4.5and RCP8.5over three time periods（i.e.2016—2035,2046—2065,and 2080—2099）.Based on simulations of the MME of the four best-fit CMIP5 models,an ongoing warming ispredicted under different RCPs in Northeast China from 2006 to 2099,especially under RCP8.5（0.53 ℃/10a）,which is twice that under RCP4.5（0.22℃/10a）.By the end of the 21 st century（2080—2099）,changes in surface air temperature tend to stabilize under RCP4.5while continuously increasing under RCP8.5.Spatially,the northern part of Northeast China generally shows greater and more rapid warming than the southern part,and the inland areas show weaker and slower warming than the coastal areas in Liaoning province.In future,the annual mean precipitation is predicted to increase but with great fluctuations.The increasing tendency from 2006 to 2099is 1.10%/10 aunder RCP4.5and 1.48%/10 aunder RCP8.5,respectively.By the end of the 21 st century（2080—2099）,the annual mean precipitation is predicted to increase by 11.24±7.77% under RCP4.5and 15.95±7.72% under RCP8.5,respectively relative to the period 1986—2005.Spatially,future change in precipitation over most parts of Northeast China is predicted to intensify,with the western part of Liaoning province changing the most.Based on the analysis of water deficit,most parts of Northeast China are projected to become wetter in the mid-tern and later period of the 21 th century under RCP4.5,while the eastern part would become wetter and the western part would become drier under RCP8.5,relative to the period 1986—2005.