山丘地形的陆面过程及边界层特征的模拟
NUMERICAL SIMULATION OF LAND SURFACE PROCESS AND ATMOSPHERE BOUNDARY LAYER STRUCTURE OVER SMALL HILL UNDERLYING SURFACE
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摘要: 将模式NP-89的陆面过程参数化方法应用到北京大学的三维复杂地形中尺度数值模式中, 得到了一个较理想的三维陆面过程及边界层模式, 利用这个改进的三维模式对20 km×20 km范围的山丘地形的陆面过程及边界层特征进行了数值模拟。模拟结果表明, 由于地形阻挡所造成山后的湍流较山前强, 进而造成近地面温度梯度和感热支出小, 最终造成山后的温度比山前的温度明显偏高; 而且随着山高的增加, 这种现象更加明显, 即该模式对山丘地形条件下的陆面过程和大气边界层特征具有较强的模拟能力; 模拟结果合理, 对研究过山气流形成机制、起伏地形大气边界层物理特征和污染物的扩散具有理论和应用价值。Abstract: A modified parameterized method of land surface physical process and a 3-dimensional transfer model are used for simulating features of surface heat flux, surface temperature, temperature profile, humidity profile, turbulence energy and so on over a small hill underlying surface.The result show s that the wind field is affected by the topography, also the turbulence transfer is affected, and the influence make the atmospheric temperature near g round surface behind the hill higher than that in front of the hill.The result is reasonable and the simulation is satisfactory.In addition, the model can also be used for other homogeneous and inhomogeneous terrain and mesoscale model.