Demonstration of a Cut-Cell Representation of 3D Orography for Studies of Atmospheric Flows over Very Steep Hills
Demonstration of a Cut-Cell Representation of 3D Orography for Studies of Atmospheric Flows over Very Steep Hills
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DOI：
10.1175/mwr-d-11-00069.1
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发表时间：
2012-02
影响因子：
3.2
通讯作者：
Sarah‐Jane Lock;H. Bitzer;A. Coals;A. Gadian;S. Mobbs
中科院分区：
文献类型：
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作者：
Sarah‐Jane Lock;H. Bitzer;A. Coals;A. Gadian;S. Mobbs
计算技术的进步使大气模式的分辨率越来越高，从而引起了模式网格捕获的底层地形的更多变化。因此，高分辨率模式必须克服与传统地形跟踪方法相关的问题，即在陡峭和复杂的地形附近产生的假风和不稳定性。地形的切割单元表示法为大气模式提供了地形跟踪垂直坐标的替代方案。这项工作探讨了一个切单元表示的理想化orographically被迫流的地形的能力。地形表面在模型中由连续的分段双线性表面表示，这些表面与规则笛卡尔网格相交，从而创建切割单元。采用近似有限体积法和对流形式的控制方程求解不规则形状的网格，并与基准orograp进行了比较。
AbstractAdvances in computing are enabling atmospheric models to operate at increasingly fine resolution, giving rise to more variations in the underlying orography being captured by the model grid. Consequently, high-resolution models must overcome the problems associated with traditional terrain-following approaches of spurious winds and instabilities generated in the vicinity of steep and complex terrain.Cut-cell representations of orography present atmospheric models with an alternative to terrain-following vertical coordinates. This work explores the capabilities of a cut-cell representation of orography for idealized orographically forced flows. The orographic surface is represented within the model by continuous piecewise bilinear surfaces that intersect the regular Cartesian grid creating cut cells. An approximate finite-volume method for use with advection-form governing equations is implemented to solve flows through the resulting irregularly shaped grid boxes.Comparison with a benchmark orograp...