Water-mass transformations in a neutral density framework and the key role of light penetration
Water-mass transformations in a neutral density framework and the key role of light penetration
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DOI：
10.1175/2007jpo3464.1
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发表时间：
2008-07-01
影响因子：
3.5
通讯作者：
McDougall, Trevor J.
中科院分区：
文献类型：
--
作者：
Iudicone, Daniele;Madec, Gurvan;McDougall, Trevor J.
本文提出了一种新的计算海洋中性输运的公式。该方法代表了一个扩展的经典诊断方法估计的水团形成的浮力平衡。包括内部源，如穿透太阳短波辐射（即，在估算表面浮力通量时，深度相关的热传递）在几个海洋区域具有重大影响，而以前的简化公式在估算表面浮力通量引起的水团形成时可能导致100%的误差。此外，在不允许短波辐射穿透的情况下，在原位数据反演中也会高估内部混合。该方法通过位温和盐度的趋势检验中性密度的演化方程。中性密度框架不需要选择参考压力，因此，与以往考虑潜在密度的方法不同，它非常适合于研究整个开阔洋水柱，该方法易于实施，特别是对于海洋数值模型。作者在这里介绍了它的应用程序，一个长期的模拟与冰海洋全球模型，使该方法得到验证。
A new formulation is proposed for the evaluation of the dianeutral transport in the ocean. The method represents an extension of the classical diagnostic approach for estimating the water-mass formation from the buoyancy balance. The inclusion of internal sources such as the penetrative solar shortwave radiation (i.e., depth-dependent heat transfer) in the estimate of surface buoyancy fluxes has a significant impact in several oceanic regions, and the former simplified formulation can lead to a 100% error in the estimate of water-mass formation due to surface buoyancy fluxes. Furthermore, internal mixing can also be overestimated in inversions of in situ data when the shortwave radiation is not allowed to be penetrative.The method examines the evolution equation of neutral density via the tendencies of potential temperature and salinity. The neutral density framework does not require the choice of a reference pressure and thus, unlike previous approaches that consider potential density, it is well suited for examining the whole open-ocean water column.The methodology is easy to implement, particularly for ocean numerical models. The authors present here its application to a long simulation made with an ice-ocean global model, which allowed the method to be validated.