Extreme rainfall in East Africa, October 2019–January 2020 and context under future climate change
Extreme rainfall in East Africa, October 2019–January 2020 and context under future climate change
复制标题
DOI：
10.1002/wea.3824
复制
发表时间：
2020-08
期刊：
影响因子：
1.9
通讯作者：
Caroline M. Wainwright;D. Finney;M. Kilavi;E. Black;J. Marsham
中科院分区：
文献类型：
--
作者：
Caroline M. Wainwright;D. Finney;M. Kilavi;E. Black;J. Marsham
2019年10月至12月东非的降雨是有记录以来最潮湿的季节之一，许多地方的降雨量是气候降雨量的两倍以上，导致整个地区发生洪水和山体滑坡。高于平均水平的降雨持续到2020年1月。持续的高降雨量也导致了2020年1月影响东非大部分地区的蝗灾。东非的潮湿条件通常与厄尔尼诺和/或正印度洋偶极子事件有关。2019年12月至12月，西印度洋出现暖异常，而东印度洋出现冷异常（正印度洋偶极子）;已知东非的降雨量高于平均水平。西印度洋的温暖异常持续到2020年1月。季节性和月度预报正确地预测了12月至12月季节的平均降雨量。一月的降雨量与西印度洋的海面温度有关。气候模型预测表明，在未来气候变化的情况下，强正印度洋偶极事件和潮湿的10月至12月季节可能会变得更加频繁，从而导致洪水风险增加。
The 2019 October-December rains over East Africa were one of the wettest seasons on record, with many locations receiving more than double the climatological rainfall, leading to floods and landslides across the region. Above average rainfall continued into January 2020. The persistently high rainfall also contributed to the locust plagues that affected much of East Africa in January 2020. Wet conditions in East Africa are typically associated with El Nino and/or positive Indian Ocean Dipole events. In October-December 2019 a warm anomaly was present in the western Indian Ocean while a cool anomaly was present in the eastern Indian Ocean (a positive Indian Ocean Dipole); conditions known to give above average rainfall over East Africa. The warm anomaly in the western Indian Ocean persisted into January 2020. Seasonal and monthly forecasts correctly predicted above average rainfall during the October-December season. January rainfall is found to be correlated with sea surface temperatures over the western Indian Ocean. Climate model projections suggest that strong positive Indian Ocean Dipole events and wet October-December seasons may become more frequent under future climate change, with associated increased risks of floods.