The impact of mixing parameterisation and bathymetry filtering on the simulated hydrography along steep continental shelf regions in terrain following ocean models
The impact of mixing parameterisation and bathymetry filtering on the simulated hydrography along steep continental shelf regions in terrain following ocean models
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混合参数化和测深过滤对海洋模型地形中陡峭大陆架区域模拟水文学的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
M. Lange
中科院分区：
文献类型：
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作者：
M. Thoma;K. Grosfeld;M. Lange
海洋模型中的一般垂直坐标可以通过三种不同的方式进行参数化：最直接和数学上最简单的方法是位势面，其中垂直坐标彼此平行并垂直于地球半径。此类海洋模型的一个例子是模块化海洋模型（MOM）（例如，Bryan & Cox，1968；Cox，1984；Haidvogel & Beckmann，1999；Griffies 等，2003）。这种 z 坐标类型模型的一个缺点是，如果研究深海和浅海架上的过程，则会浪费多个节点（从而浪费计算成本）。如果没有额外的经验底部边界层混合方案，这种类型的海洋模型也无法充分模拟溢流过程（例如，Beckmann & Döscher，1997；Ezer & Mellor，2004）。也许最自然的垂直坐标系是等重坐标系，其中表面沿恒定密度定向。这种类型的模型不会发生虚假的双相混合，但垂直坐标是自适应的，并且必须在每个时间步长重新计算。此外，还需要对表面和底部边界层进行特殊处理，从而导致额外的复杂性和计算成本。最常见的等密度海洋模型是迈阿密等密度模型（MICOM）（例如，Bleck，1978；Haidvogel & Beckmann，1999）。第三种海洋模型使用地形跟随坐标。这些 σ−坐标模型最方便地表示底部地形。到目前为止，它们主要用于高分辨率区域模型，其中与此类模型相关的压力梯度误差（例如，Haney，1991）可能不太重要（Ezer 等，2002）。使用地形跟随坐标的模型有 Princton 海洋模型 (POM) (Blumberg & Mellor, 1987)、s 坐标原始方程模型 (SPEM) (Haidvogel et al., 1991) 和 Rombax (Thoma et al., 2005b)。
General vertical coordinates in ocean models can be parameterised in three different ways: The most straightforward and mathematical easiest method are geopotential surfaces, where vertical coordinates are parallel to one another and perpendicular to the earth’s radius. One example for this type of ocean models is the Modular Ocean Model (MOM) (e.g., Bryan & Cox, 1968; Cox, 1984; Haidvogel & Beckmann, 1999; Griffies et al., 2003). One disadvantage of this z−coordinate type models is that several nodes (and therefore computational costs) are wasted if processes in the deep ocean and on shallow shelves are investigated. This type of ocean models is also not able to simulate overflow process adequately without additional empirical bottom boundary layer mixing schemes (e.g., Beckmann & Döscher, 1997; Ezer & Mellor, 2004). The perhaps most natural vertical coordinate system is an isopycnal one, where the surfaces are orientated along constant densities. No spurious diapycnal mixing occurs in this type of model, but the vertical coordinates are adaptive and must be recalculated each timestep. In addition, a special treatment of surface and bottom boundary layers is necessary, leading to additional complexity and computational costs. The most common isopycnic ocean model is the Miami Isopycnic Model (MICOM) (e.g., Bleck, 1978; Haidvogel & Beckmann, 1999). The third type of ocean models uses terrain following coordinates. These σ−coordinate models are most convenient to represent the bottom topography. So far they are mainly used in high resolution regional models where the pressure gradient error, associated with this type of models (e.g., Haney, 1991) is probably of minor importance (Ezer et al., 2002). Models using terrain following coordinates are the Princton Ocean Model (POM) (Blumberg & Mellor, 1987), the s-coordinate primitive equation model (SPEM) (Haidvogel et al., 1991) and Rombax (Thoma et al., 2005b).