Adjustment of the Meridional Overturning Circulation and Its Dependence on Depth of Mixing
Adjustment of the Meridional Overturning Circulation and Its Dependence on Depth of Mixing
复制标题
经向翻转环流的调节及其对混合深度的依赖性
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
G. Hughes
中科院分区：
文献类型：
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作者：
C. Vreugdenhil;A. Hogg;R. W. Griffiths;G. Hughes
本文研究了平流过程和混合作用对纬向翻转环流时间调整的相对作用，特别是混合作用在深海或大洋上层的影响。对流驱动翻转和施加搅拌速率的实验室实验表明，循环调整向平衡状态的时间尺度上的混合在上边界层区域，但独立的混合速率在大部分的内部。分层的平衡状态仅取决于边界层中的混合速率。一个理想化的高分辨率海洋模型显示调整（一个两单元环流）主要由平流通风时间尺度，一致的看法，主要发生在表面附近的水团转换确定的环流。试验和模型结果均表明，环流的调节是由表面浮力的吸收（或排斥）和表面浮力的变化来控制的。
AbstractThe relative roles of advective processes and mixing on the temporal adjustment of the meridional overturning circulation are examined, in particular the effects of mixing in either the abyssal or upper ocean. Laboratory experiments with convectively driven overturning and imposed stirring rates show that the circulation adjusts toward an equilibrium state on time scales governed by mixing in the upper boundary layer region but independent of the mixing rate in the bulk of the interior. The equilibrium state of the stratification is dependent only on the rate of mixing in the boundary layer. An idealized high-resolution ocean model shows adjustment (of a two-cell circulation) dominated primarily by the advective ventilation time scale, consistent with a view of the circulation determined by water mass transformation occurring primarily near the surface. Both the experiments and the model results indicate that adjustments of the circulation are controlled by surface buoyancy uptake (or rejection) a...