AN EXAMPLE OF EDDY-INDUCED OCEAN CIRCULATION
AN EXAMPLE OF EDDY-INDUCED OCEAN CIRCULATION
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DOI：
10.1175/1520-0485(1980)010
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发表时间：
1980-01-01
影响因子：
3.5
通讯作者：
RHINES, PB
中科院分区：
文献类型：
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作者：
HOLLAND, WR;RHINES, PB
为了阐明涡旋在海洋环流中的作用，对单个数值实验进行了涡旋尺度和局部涡度平衡的检验。由于流的复杂性，需要结合不同的分析。特别是计算了平均位涡场，并将其与局部和全局涡通量联系起来。根据流体中的涡流熵平衡，讨论了涡流产生和衰减的性质。应用环流定理推导了环流各部分的动量平衡。确定了位涡和热混合时的涡扩散场。考察了Sverdrup动力学在流体各部分的适用性以及深海环流的驱动方式。网络画面是一个复杂而一致的画面。在上层，涡的产生主要发生在东向急流分离区和西向回流区。涡旋衰减主要发生在自由射流的东端，伴随着上升梯度的热和位涡涡旋通量。下层由界面处的无粘压力从上层驱动。，在低层到处都伴随着下降梯度的位涡通量。深层动力学本质上是一个“湍流”的Sverdrup平衡，Ū3·∇Q´3=∇·κ∇Q´3，由涡流而不是风应力驱动。
Gyre scale and local vorticity balances are examined for a single numerical experiment designed to elucidate the role of eddies in the oceanic general circulation. Due to the complex nature of the flow, a combination of different analyses is needed. In particular the mean potential vorticity fields are calculated and related to local and global vorticity fluxes. The nature of eddy generation and decay is discussed in terms of eddy enstrophy balances in the fluid. Momentum balances in various parts of the gyre are deduced through the application of the circulation theorem. Fields of eddy diffusivity for the mixing of potential vorticity and heat are determined. The applicability of Sverdrup dynamics in various parts of the fluid and the manner in which the deep abyssal gyres are driven are examined.The net picture is a complex but consistent one. In the upper layer, eddy generation occurs in the separation region of the eastward jet and in the region of westward return flow. Eddy decay occurs principally at the eastern end of the free jet accompanied by upgradient eddy fluxes of heat and potential vorticity. The lower layer is driven from above by inviscid pressure forcing at the interface., this is accompanied by downgradient potential vorticity flux everywhere in the lower layer. The deep dynamics is essentially a “turbulent” Sverdrup balance, Ū3·∇ Q̄3= ∇·κ ∇Q̄3, driven by eddy rather than wind stresses.