A window on the deep ocean: The special value of ocean bottom pressure for monitoring the large-scale, deep-ocean circulation
A window on the deep ocean: The special value of ocean bottom pressure for monitoring the large-scale, deep-ocean circulation
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DOI：
10.1016/j.pocean.2018.01.011
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发表时间：
2018-02-01
影响因子：
4.1
通讯作者：
Stepanov, Vladimir
中科院分区：
文献类型：
--
作者：
Hughes, Chris W.;Williams, Joanne;Stepanov, Vladimir
我们展示了如何通过专注于海底压力测量，特别是在全球大陆坡度上的测量，有可能避免主导深海大多数可观测到的中尺度可变性的“雾”。这使监测海洋环流的那些方面成为可能，因为这些方面对全球规模、海洋多变性和气候最为重要。因此，我们认为，这种测量应被视为全球海洋观测系统未来的一个重要组成部分，以补充目前的公海和沿海要素。我们的结论既基于理论论证，也基于一个高分辨率海洋模式的诊断，该模式具有真实的中尺度变率幅度和频谱。这些结果表明，对于几种垂直模式，边界压力变化在沿斜坡距离数万公里的范围内是一致的。我们通过确定边界波和赤道波完成北部盆地一圈的时间(第一和第二垂直模分别为115天和205天)，说明了这一点在模式大西洋中的价值，展示了边界特征与盆地尺度理论模式的比较，并展示了利用这些边界测量监测经向翻转环流的能力。最后，我们讨论了对真实海洋的适用性，并就如何在不受仪器漂移污染的情况下进行此类测量提出了建议。
We show how, by focusing on bottom pressure measurements particularly on the global continental slope, it is possible to avoid the "fog" of mesoscale variability which dominates most observables in the deep ocean. This makes it possible to monitor those aspects of the ocean circulation which are most important for global scale ocean variability and climate. We therefore argue that such measurements should be considered an important future component of the Global Ocean Observing System, to complement the present open-ocean and coastal elements. Our conclusions are founded on both theoretical arguments, and diagnostics from a fine-resolution ocean model that has realistic amplitudes and spectra of mesoscale variability. These show that boundary pressure variations are coherent over along-slope distances of tens of thousands of kilometres, for several vertical modes. We illustrate the value of this in the model Atlantic, by determining the time for boundary and equatorial waves to complete a circuit of the northern basin (115 and 205 days for the first and second vertical modes), showing how the boundary features compare with basin-scale theoretical models, and demonstrating the ability to monitor the meridional overturning circulation using these boundary measurements. Finally, we discuss applicability to the real ocean and make recommendations on how to make such measurements without contamination from instrumental drift.