RCPs情景下中国21世纪气候变化预估及不确定性分析

PREDICTION OF CLIMATE CHANGE OVER CHINA AND UNCERTAINTY ANALYSIS DURING THE 21ST CENTURY UNDER RCPS

利用CMIP5提供的26个全球气候系统模式的集合模拟结果,预估新代表性浓度路径情景下,中国区域21世纪温度和降水的变化,并采用泰勒图和模式离差法对多模式预估结果进行不确定性分析。预估结果显示到21世纪末期(2081—210年),三种浓度路径情景(RCP2.6、RCP4.5、RCP8.5)下中国年均温增幅分别为1.87℃、2.88℃、5.51℃;年降水的增幅分别为0.124 mm/d、0.214 mm/d、0.323 mn/d。21世纪中国增温增湿的主要贡献区为青藏高原和东北地区。不确定性分析结果表明,大多数CMIP5模式对21世纪中国区域温度的预估有较好的一致性,而对降水预估的差异性相对较大。集合模式离差分析结果表明,中国80%以上区域的温度预估结果信号大于噪音,而降水预估的有意义信号区域不足20%,CMIP5集合模式对温度变化预测结果的可信度较高,而对降水变化的预测结果则存在很大的不确定性。

Based on the integrated simulations of 26 global climate models provided by CMIP5 （Coupled Model Inter-comparison Project）, this paper predicted the changes of temperature and precipitation of China in the 21st century under the new representative concentration pathways （RCPs） ,＇ and analyzed uncertainties of the predictions by Taylor diagram and deviation. Results showed that the increase of average annual temperature of China using three RCPs （RCP2.6, RCP4. 5, RCP8.5） was 1.87 ℃, 2.88 ℃ and 5.51 ℃, respectively, and the increase of average annual precipitation using the three RCPS was 0. 124 mm/d, 0. 214 mm/d, and 0. 323 mm/d, respectively. The increased temperature and precipitation in the 21st century were mainly contributed by the Tibetan Plateau and the northeast of China. The results of uncertainty analysis showed that most CMIP5 models have a good consistency in predicting the temperature while having a relatively large deviation in predicting the precipitation of China in the 21st century. The deviation analysis showed that more than 80% of the areas of China have greater signals than noises for temperature prediction, but the areas that have meaningful signals for precipitation prediction are less than 20%. Thus, a multi-model ensemble of CMIP5 is more reliable on predicting temperature than precipitation due to the large uncertainties of precipitation.