A numerical study of the Chicago lake breeze
A numerical study of the Chicago lake breeze
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芝加哥湖风的数值研究
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
A. Kistler
中科院分区：
文献类型：
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作者：
A. Patrinos;A. Kistler
提出了一个二维数值模型来研究芝加哥地区的湖风。以前的工作人员在该领域使用的流体静力近似并未被采用。相反，完整的 z 动量方程得到求解，并且连续性方程保留其原始形式。数值模型采用交错网格，并采用交替方向隐式方法对方程进行积分。无需外部滤波器、上游空间差分或人工水平扩散项即可实现计算稳定性。在实际初始条件但简化边界条件下获得的结果与 Lyons 在 1967 年芝加哥湖微风观测研究中获得的观测结果相当不错。下边界条件的限制形式包括观测到的风速和微风的其他运动学特征。在各种“涡流扩散率”模型中，“涡流扩散率”随高度恒定的模型可产生最真实的结果。 “涡流扩散率”随高度降低的模型显示上层的流动模式不切实际。微风开始时大气的稳定性对环流强度有显着影响，但对流入层的厚度没有影响，流入层的厚度似乎对所涉及参数的大幅变化相当不敏感。
A two-dimensional numerical model is presented for the study of the Chicago area lake breeze. The hydrostatic approximation used by previous workers in this field is not employed. Instead, the complete z-momentum equation is solved and the equation of continuity is retained in its original form. The numerical model employs a staggered mesh, and Alternating Direction Implicit methods are used for the integration of the equations. Computational stability is achieved without external filters, upstream space differencing, or artificial horizontal diffusion terms.The results obtained for realistic initial conditions but simplified boundary conditions compare reasonably well with observations obtained by Lyons in his 1967 observational study of the Chicago lake breeze. Limiting forms of the lower boundary condition bracket the observed wind speeds and other kinematic features of the breeze. Among the various ‘eddy diffusivity’ models, that with constant ‘eddy diffusivity’ with height produces the most realistic results. The models with a decrease of ‘eddy diffusivity’ with height show unrealistic flow patterns in the upper layers. The stability of the atmosphere at the onset of the breeze is shown to have a pronounced effect on the intensity of the circulation, but not on the thickness of the inflow layer, which appears quite insensitive to large changes in the parameters involved.