The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient
The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient
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DOI：
10.1088/1748-9326/9/12/124007
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发表时间：
2014-12-01
影响因子：
6.7
通讯作者：
Loup Guyot, Jean
中科院分区：
文献类型：
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作者：
Carlo Espinoza, Jhan;Marengo, Jose Antonio;Loup Guyot, Jean
据报道，2014年夏季（12月至3月）亚马逊西南部前所未有的潮湿条件，降雨量比正常水平高出约100%。马德拉河排放量（亚马逊南部主要支流）已经比正常水平高出74%（韦略港58 000 m（3）s（-1））和380%（25 000 m（3）s（-1）），位于安第斯山脉出口处的鲁雷纳巴克，而2014年6月马瑙斯的里奥内格罗水位为29.47 m，相当于里奥内格罗113年来的第五高记录。虽然亚马逊河流域以前的洪水与拉尼娜现象和/或比正常热带南大西洋温暖有关，但2014年的降雨和洪水异常与西太平洋-印度洋的温暖状况以及异常温暖的亚热带南大西洋有关。我们的研究结果表明，热带和亚热带南大西洋SST梯度是从大西洋向亚马逊西南部输送水分的主要驱动力，这在2014年夏季变得异常强烈。
Unprecedented wet conditions are reported in the 2014 summer (December-March) in Southwestern Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m(3) s(-1)) at Porto Velho and 380% (25 000 m(3) s(-1)) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Nina and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014.