High‐latitude eruptions cast shadow over the African monsoon and the flow of the Nile
High‐latitude eruptions cast shadow over the African monsoon and the flow of the Nile
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DOI：
10.1029/2006gl027665
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发表时间：
2006-09
影响因子：
5.2
通讯作者：
L. Oman;A. Robock;G. Stenchikov;T. Thordarson
中科院分区：
文献类型：
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作者：
L. Oman;A. Robock;G. Stenchikov;T. Thordarson
尼罗河记录显示，在1783-1784年的拉基火山爆发以及其他高纬度火山爆发之后，尼罗河流量非常低。气候模式对拉基火山爆发的模拟显示，1783年夏季，北方半球大陆显著降温（−1°至−3°C），导致非洲和印度季风环流减弱，非洲萨赫勒地区降水异常，日降水量为−1至−3毫米，从而产生了低尼罗河流。未来的高纬度喷发将严重影响这些地区的食物和水供应。通过对尼罗河流量的观测，这一新的认识被用来支持冰岛Eldgjá火山爆发开始的日期为939年，这是过去1500年来最大的高纬度火山爆发。
Nile River records indicate very low flow following the 1783–1784 Laki volcanic eruption, as well as after other high‐latitude volcanic eruptions. As shown by climate model simulations of the Laki eruption, significant cooling (−1° to −3°C) of the Northern Hemisphere land masses during the boreal summer of 1783 resulted in a strong dynamical effect of weakening the African and Indian monsoon circulations, with precipitation anomalies of −1 to −3 mm/day over the Sahel of Africa, thus producing the low Nile flow. Future high‐latitude eruptions would significantly impact the food and water supplies in these areas. Using observations of the flow of the Nile River, this new understanding is used to support a date of 939 for the beginning of the eruption of the Eldgjá volcano in Iceland, the largest high‐latitude eruption of the past 1500 years.