Tidal mixing processes amid small-scale, deep-ocean topography
Tidal mixing processes amid small-scale, deep-ocean topography
复制标题
DOI：
10.1002/2014gl062755
复制
发表时间：
2015-01-28
影响因子：
5.2
通讯作者：
Inall, Mark E.
中科院分区：
文献类型：
--
作者：
Dale, Andrew C.;Inall, Mark E.
潮汐-地形相互作用的性质反映了水体在潮汐漂移期间所经历的地形尺度。在深海中，这些尺度通常在千米以下，但在这样的尺度上对潮汐过程的直接观测还很缺乏。在一个网站，鞍在陡峭和复杂的大西洋中脊地形，观测揭示潮汐脉冲，底部被困的前，溢出，和背风波的潮汐结合类似幅度的平均流量。锋面和溢流的潮汐脉动仅在局部明显，其相位在数百米的尺度上变得不可预测。在100-200米厚的底边界层中增强的湍流的耗散率估计为2.6x10（-2）Wm（-2），超过了大洋中脊环境中潮汐耗散的大尺度平均值，但还不到一个数量级。这个地点不是一个耗散热点，观测到的过程可以提供广泛分布的混合到纬向翻转环流。
The nature of tide-topography interaction reflects the topographic scales experienced by water parcels during their tidal excursions. In the deep ocean these scales are typically subkilometer, yet direct observations of tidal processes on such scales are lacking. At one site, a saddle amid steep and complex Mid-Atlantic Ridge topography, observations reveal tidally pulsed, bottom-trapped fronts, overflows, and lee waves in response to a tide combined with a mean flow of similar amplitude. The tidal pulsing of the fronts and overflows was only evident locally, and their phase became unpredictable over scales of hundreds of meters. Enhanced turbulence in a 100-200 m thick bottom boundary layer had an estimated dissipation rate of 2.6x10(-2)Wm(-2), exceeding the large-scale average of tidal dissipation in mid-ocean ridge environments but by less than an order of magnitude. This site was not a dissipation hotspot, and the processes observed could provide widely distributed mixing to the meridional overturning circulation.