Episodic warming of near-bottom waters under the Arctic sea ice on the central Laptev Sea shelf
Episodic warming of near-bottom waters under the Arctic sea ice on the central Laptev Sea shelf
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DOI：
10.1002/2015gl066565
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发表时间：
2016-01-16
影响因子：
5.2
通讯作者：
Timokhov, Leonid
中科院分区：
文献类型：
--
作者：
Janout, Markus;Hoelemann, Jens;Timokhov, Leonid
多年系泊记录(2007-2014年)和卫星图像突出了拉普特夫海强烈的温度变异性和独特的水文性质。北冰洋大陆架是河流排放、海冰形成和出口的关键区域，包括海底永久冻土和甲烷矿藏，这强调需要了解海底附近的热力变化。最近几年的特点是冰层提前消退，近岸环境变暖。然而，在更深的大陆架上没有观察到变暖，直到2012/2013年冬季全年冰下测量记录到史无前例的+0.6摄氏度的近海底温度，就在北冰洋海冰面积达到创纪录的最低水平之后。在拉普特夫海，2012年的早期冰川消退，加上莱纳河的热量和太阳辐射，产生了夏季异常温暖的表层水，这些水垂直混合，被困在排水层中，随后向海底转移，直到海水排出侵蚀层化时水柱冷却。
A multiyear mooring record (2007-2014) and satellite imagery highlight the strong temperature variability and unique hydrographic nature of the Laptev Sea. This Arctic shelf is a key region for river discharge and sea ice formation and export and includes submarine permafrost and methane deposits, which emphasizes the need to understand the thermal variability near the seafloor. Recent years were characterized by early ice retreat and a warming near-shore environment. However, warming was not observed on the deeper shelf until year-round under-ice measurements recorded unprecedented warm near-bottom waters of +0.6 degrees C in winter 2012/2013, just after the Arctic sea ice extent featured a record minimum. In the Laptev Sea, early ice retreat in 2012 combined with Lena River heat and solar radiation produced anomalously warm summer surface waters, which were vertically mixed, trapped in the pycnocline, and subsequently transferred toward the bottom until the water column cooled when brine rejection eroded stratification.