Projected effects of 1.5 °C and 2 °C global warming levels on the intra-seasonal rainfall characteristics over the Greater Horn of Africa
Projected effects of 1.5 °C and 2 °C global warming levels on the intra-seasonal rainfall characteristics over the Greater Horn of Africa
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DOI：
10.1088/1748-9326/ab6b33
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发表时间：
2020-03-01
影响因子：
6.7
通讯作者：
Atheru, Zachary
中科院分区：
文献类型：
--
作者：
Gudoshava, Masilin;Misiani, Herbert O.;Atheru, Zachary
这项研究探讨了1.5摄氏度和2摄氏度的全球变暖水平（GWLs）对大非洲之角季节内降雨特征的影响。根据协调区域气候降尺度实验项目的25个成员区域多模式集合的输出结果分析了影响。区域气候模式由耦合模式相互比较项目第5阶段全球气候模式（RCP 8.5）的历史和未来时期驱动。我们分析了该地区的三个主要季节，即3月至5月，6月至9月和6月至12月。结果表明，在1.5摄氏度和2摄氏度的GWLs，特别是6月至9月和12月至12月的季节平均季节内降雨特征的广泛强劲的变化。预计3月至5月的季节将在GWL的两种情况下发生变化，季节开始和结束都提前。在6月至9月的雨季，有明显迹象表明，北方部分地区的雨季开始时间推迟，连续潮湿日数减少，雨季长度缩短，低于2摄氏度的GWL。在12月至12月的季节期间，预计该区域将出现迟发、延迟停止、连续潮湿日数减少以及赤道地区大部分地区在2摄氏度GWL下的季节较长。这些结果表明，关键是要限制GWL低于1.5摄氏度，因为1.5摄氏度和2摄氏度GWL之间的差异在某些情况下加剧了大非洲之角季节内降雨特征的变化。
This study examines the effects of 1.5 degrees C and 2 degrees C global warming levels (GWLs) on intra-seasonal rainfall characteristics over the Greater Horn of Africa. The impacts are analysed based on the outputs of a 25-member regional multi-model ensemble from the Coordinated Regional Climate Downscaling Experiment project. The regional climate models were driven by Coupled Model Intercomparison Project Phase 5 Global Climate Models for historical and future (RCP8.5) periods. We analyse the three major seasons over the region, namely March-May, June-September, and October-December. Results indicate widespread robust changes in the mean intra-seasonal rainfall characteristics at 1.5 degrees C and 2 degrees C GWLs especially for the June-September and October-December seasons. The March-May season is projected to shift for both GWL scenarios with the season starting and ending early. During the June-September season, there is a robust indication of delayed onset, reduction in consecutive wet days and shortening of the length of rainy season over parts of the northern sector under 2 degrees C GWL. During the October-December season, the region is projected to have late-onset, delayed cessation, reduced consecutive wet days and a longer season over most of the equatorial region under the 2 degrees C GWL. These results indicate that it is crucial to limit the GWL to below 1.5 degrees C as the differences between the 1.5 degrees C and 2 degrees C GWLs in some cases exacerbates changes in the intra-seasonal rainfall characteristics over the Greater Horn of Africa.