摘要
利用政府间气候变化专门委员会第5次评估报告(IPCC AR5)耦合模式相互比较计划第5阶段(CMIP5)中所包含的8个模式资料,对长江中下游强降水的气候特征在21世纪的变化进行预估,并与此前基于第3阶段(CMIP3)的7个模式的预估结果进行了对比。所用资料既包括模式对20世纪的历史模拟,也包括它们在未来高、中、低三种排放情景(即RCP8.5、RCP4.5、RCP2.6三种代表性浓度路径)下的预估试验资料。结果表明:1)不同模式的预估结果有较好的一致性。相对于20世纪最后20 a(1980—1999年),21世纪不仅强降水事件频次、强降水事件的平均强度增加,且年际变率也有所增强。就增加幅度而言,西部强度较小,东部强度较大。2)就不同排放情景相互比较而言,在低排放情景和高排放情景(RCP2.6和RCP8.5)下,降水强度和频次的增长均比在中等排放情景(RCP4.5)下大。3)与之前CMIP3的结果相比,尽管二者均预估未来降水强度和频次增长,但二者增加幅度的空间分布并不一致。在CMIP5中,表现为自西向东幅度递增的特点,而在CMIP3中则中部地区增幅最大。
This paper evaluates the future projection of heavy rainfall events in the middle and lower reaches of the Yangtze River valley based on outputs of eight coupled models attending the Coupled Model Intercomparison Project phase 5( CMIP5) from IPCC AR5. The experiments under different representative concentration pathways( RCPs) are compared with each other,and with the previous CMIP3 experiments as well. The outputs from the historical simulation of CMIP5 are also utilized as a base to derive future trends. The results suggest an agreement among all the CMIP5 models,in that both the strength and the occurrence frequency of heavy rainfall events are projected to increase in the 21 st century relative to the last twenty years of the 20 th century(1980—1999). In contrast,the strength increase in the east of the re-gion is even greater than that in the west. Besides,the interannual variability of heavy rainfall events is also projected to enhance in the future. As for different RCPs,the projected increases in the strength and occurrence frequency of heavy rainfall events in RCP2. 6 and RCP8. 5 are greater than those in RCP4. 5. In comparison to CMIP3,the projected increases in the strength and occurrence frequency are even larger,albeit a significant difference in the spatial distribution in the latter projection. The projected maximum increase in the rainfall amplitude in CMIP3 is located in the central region,while it is in the east of the region in CMIP5.
出处
《大气科学学报》
CSCD
北大核心
2014年第5期529-540,共12页
Transactions of Atmospheric Sciences
基金
公益性行业(气象)科研专项(GYHY201006022)
中国科学院战略性先导专项(XDA05090406)
关键词
CMIP5试验
RCPs
长江中下游
强降水
预估
CMIP5 test
RCPs
middle and lower reaches of Yangtze River valley
heavy rainfall
projection
