Abyssal Upwelling in Mid‐Ocean Ridge Fracture Zones
Abyssal Upwelling in Mid‐Ocean Ridge Fracture Zones
复制标题
大洋中脊断裂带的深渊上升流
DOI：
10.1002/2017gl075872
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
A. Thurnherr
中科院分区：
文献类型：
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作者：
L. Clement;A. Thurnherr
深海中的湍流通过维持翻转环流的最深处分支，在气候系统中发挥着重要作用。在南大西洋中大西洋洋脊的西翼，先前观测到的深海水的底部增强和潮汐调节混合似乎暗示了深海和底部水的反直觉密度化。然而，在裂缝带内部，由于向下传播的近惯性波能量增强，湍流从海底上升，而这种能量在亚惯性剪切最大值以下衰减。射线追踪模拟预测了波-平均流相互作用后波能量的衰减。假设的波-平均流相互作用驱动巴西盆地洋中脊侧翼的深层流向密度低至0.6 Sv的方向流动，同样的过程也可能导致其他洋中脊带断裂带的海洋盆地的深海水上升流。
Turbulence in the abyssal ocean plays a fundamental role in the climate system by sustaining the deepest branch of the overturning circulation. Over the western flank of the Mid‐Atlantic Ridge in the South Atlantic, previously observed bottom‐intensified and tidally modulated mixing of abyssal waters appears to imply a counterintuitive densification of deep and bottom waters. Here we show that inside fracture zones, however, turbulence is elevated away from the seafloor because of intensified downward propagating near‐inertial wave energy, which decays below a subinertial shear maximum. Ray‐tracing simulations predict a decay of wave energy subsequent to wave‐mean flow interactions. The hypothesized wave‐mean flow interactions drive a deep flow toward lighter densities of up to 0.6 Sv over the mid‐ocean ridge flank in the Brazil Basin, and the same process may also cause upwelling of abyssal waters in other ocean basins with mid‐ocean ridges with fracture zones.
影响因子：
3.5
作者：
de Lavergne, Casimir;Madec, Gurvan;Garabato, Alberto C. Naveira
通讯作者：
Garabato, Alberto C. Naveira