青藏高原气温和降水近期、中期与长期变化的预估及其不确定性来源  

The near-term,mid-term and long-term projections of temperature and precipitation changes over the Tibetan Plateau and the sources of uncertainties

作　　者：周天军[1,2] 张文霞 陈晓龙 张丽霞 邹立维[1] 满文敏[1] ZHOU Tianjun;ZHANG Wenxia;CHEN Xiaolong;ZHANG Lixia;ZHOU Liwei;MAN Wenmin(Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院大气物理研究所,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《气象科学》2020年第5期697-710,共14页Journal of the Meteorological Sciences

基　　金：中国科学院战略性先导科技专项(XDA20060102);国家自然科学基金资助项目(41988101)。

摘　　要：采用第五次耦合模式比较计划(Coupled Model Intercomparison Project Phase 5,CMIP5)高分辨率全球统计降尺度预估数据集,针对近期(2020-2039年)、中期(2040-2059年)和长期(2080-2099年),以及全球1.5℃和2℃温升阈值,预估了青藏高原地区平均气温和降水、极端气温和极端降水的变化,定量估算了预估结果的不确定性来源。结果表明:(1)在RCP4.5和RCP8.5情景下,21世纪青藏高原地区平均气温和降水、极端气温和极端降水强度均显著增加,最长连续干旱天气减少。高原气候变化幅度超全球平均,至21世纪末,模式集合预估的气候变化幅度介于全球平均的1.5~3倍。(2)青藏高原地区受0.5℃额外增温的显著影响,年均气温、极端高温和极端低温均显著升高,平均及极端强降水均显著增加。(3)排放情景的选择对近期气候预估影响小,但对长期影响大。在相同排放情景下,内部变率主导了近期高原平均气温预估的不确定性,但至长期其贡献降至10%以下。模式和内部变率的不确定性对降水预估均有贡献,且都随时间减小,最大不确定性中心位于西部和北部边缘,噪声与信号比大于6。The mean and extreme temperature and precipitation changes in the future were explored by using the global high-resolution downscaled projections from the Coupled Model Intercomparison Project phase 5(CMIP5).The ranges and sources of projection uncertainties of the mean state changes are also estimated.Results show that:(1)under both RCP4.5 and RCP8.5 scenarios,the mean temperature and precipitation,and extreme temperature and precipitation increase,while the consecutive dry days decrease,over TP in the 21st century.The rates of climate changes over TP are faster than global mean,and the changes over TP are 1.5-3 times higher than the global average at the end of 21st century.(2)The response of TP to a half-degree warming increment is significant in both mean and extreme temperature,mean and extreme precipitation.(3)Scenario uncertainty shows relative smaller contributions for the near-term projection than for the long-term.Under the same emission scenario,internal variability dominates the near-term uncertainties of TP mean temperature projection,but in the long-term,its contribution falls below 10%.Both model uncertainty and internal variability contribute to the mean precipitationchanges,andthe contributions decrease with time.The largest uncertainty in TP precipitation projection is located at the western and northern edges of TP,where the noise-signal ratioislarger than 6.

关 键 词：青藏高原 气候预估 NEX-GDDP 极端事件 预估不确定性 

分 类 号：P467[天文地球—大气科学及气象学]