On the parameterization of eddy transfer. Part I. Theory
On the parameterization of eddy transfer. Part I. Theory
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涡流传递参数化研究.
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
P. Killworth
中科院分区：
文献类型：
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作者：
P. Killworth
这是三篇链接论文中的第一篇，该论文为平均流开发了涡流参数化方案，该方案比变形半径更宽。该方案部分基于线性不稳定性中的位涡和厚度通量的行为，其中前者是下降梯度的（除了转动矩阵，不存在于通道模型中），而后者不是精确下降的，除了在 f 平面上。该方案导致扩散率随深度变化很大，并且在表面和地板处最小。内在的δ函数通量也出现在地表和地板上，这些都被详细计算出来。结果表明，所有此类参数化方案（无论是否与线性不稳定性相关）都必须满足垂直积分形式的必要一致性条件。均匀扩散率不能满足此要求，除非它被定义为在表面和地板上消失。给出了两种有效计算近似扩散率的方法，它们的结果与不稳定性理论的精确结果很好地比较。
This is the first of three linked papers which develop an eddy parameterization scheme for mean flows which are wide compared with a deformation radius. The scheme is partly based on the behavior of potential vorticity and thickness fluxes in linear instability, where the former are downgradient (apart from a turning matrix, not present in channel models) and the latter are not precisely downgradient, except on an f-plane. The scheme leads to a diffusivity which varies quite strongly with depth and is smallest at surface and floor. Intrinsic delta-function fluxes also occur at surface and floor, and these are worked out in detail. It is shown that all such parameterization schemes (whether linked to linear instability or not) must satisfy a necessary consistency condition, in the form of a vertical integral. A uniform diffusivity does not satisfy this requirement unless it is defined to vanish at surface and floor. Two methods to compute approximate diffusivities efficiently are given, and their results compare well with exact results from instability theory.