文章基本信息

标题：How slippery are piecewise-constant coastlines in numerical ocean models?
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作者：Alistair Adcroft ; David Marshall
期刊名称：Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN：1600-0870
出版年度：1998
卷号：50
期号：1
页码：95-108
DOI：10.3402/tellusa.v50i1.14514
摘要：Coastlines in numerical ocean models are oriented at various finite angles to the model grid.The true coastline is usually replaced by a piecewise-constant approximation in which the modelcoastline is everywhere aligned with the model grid. Here we study the consequences of thepiecewise-constant approximation in an idealised shallow-water ocean model. By rotating thenumerical grid at various finite angles to the physical coastlines, we are able to isolate theimpact of piecewise-linear boundaries on the model circulation. We demonstrate that piecewiseconstantcoastlines exert a spurious form stress on model boundary currents, dependent onboth the implementation of the slip boundary condition and the form of the viscous stresstensor. In particular, when free-slip boundary conditions are applied, the character of thecirculation can be reduced to no-slip in the presence of a piecewise-constant boundary. Thespurious form stress can be avoided in a free-slip limit if the viscous stress tensor is written interms of vorticity and divergence.