The transport of warm Atlantic Waters north of Svalbard is one of the major heat and salt sources to the Arctic Ocean. The circulation pathways and the associated heat transport influence the variability in the Arctic sea ice extent, the onset of freezing, and marine ecosystems. We present observations obtained from research cruises and an autonomous underwater glider mission in summer and fall 2018, to describe the hydrographic structure, volume transport, and circulation patterns of the warm Atlantic Water Boundary Current between 12°E and 24°E north of Svalbard. The Atlantic Water volume transport reaches a maximum of 3.0 ± 0.2 Sv in October, with an intraseasonal variability of 1 Sv (1 Sv = 10⁶ m³ s⁻¹). During summer and late fall, we observed an Atlantic Water recirculation flowing westward (0.1–0.2 Sv) in the outer part of the section away from the shelf break. This counter current appears to be a part of an anticyclonic circulation in the Sofia Deep. The strength of the Atlantic Water recirculation and the Atlantic Water boundary current is very sensitive to the wind stress curl: The boundary current volume transport doubled in less than a week, corresponding to a transition from strongly negative (−10⁻⁶ N m⁻³) to strongly positive (10⁻⁶ N m⁻³) wind stress curl over the Sofia Deep. A previously unknown, deep bottom‐intensified current is observed to flow parallel to the boundary current, between the 1,500 and 2,000 m isobaths. Historical data in the region support the presence of the bottom‐intensified current.

中文翻译：

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根据2018年夏季和秋季的观测，斯瓦尔巴特群岛以北的大西洋水的结构和运输

斯瓦尔巴特群岛以北的温暖大西洋水域的运输是北冰洋的主要热量和盐分来源之一。循环路径和相关的热传输影响北极海冰范围的变化，冰冻的开始以及海洋生态系统。我们将展示从研究航行和2018年夏季和秋季的自主水下滑翔机任务获得的观测结果，以描述斯瓦尔巴特群岛以北12°E至24°E之间大西洋海温边界流的水文结构，体积传输和环流模式。十月份的大西洋水运量最高达到3.0±0.2 Sv，季节内变化为1 Sv（1 Sv = 10 ⁶ m ³ s ^-1）。在夏季和秋季末期，我们在远离架子断裂的部分外部观察到大西洋水回流向西（0.1-0.2 Sv）。这种逆流似乎是索非亚深部反气旋循环的一部分。大西洋水再循环和大西洋水边界电流的强度对风应力卷曲非常敏感：边界电流的体积输运在不到一周的时间内增加了一倍，对应于从强负值（-10 ^-6 N m ^-3的转变））到强正值（10 ^-6 N m ^-3）风在Sofia Deep上卷曲。观察到一个以前未知的深部底部增强电流在1,500至2,000 m等值线之间平行于边界电流流动。该地区的历史数据支持存在底部增强电流。