通过求解含有摩擦耗散的线性化大气动力学方程组,得到了在夜间稳定大气边界层中小尺度地形产生的波动阻力和形式阻力的解析解.结果表明边界层中的稳定度、风速和湍流状态、边界层厚度、上部残余层中的稳定度和风速以及地形高度和坡度,都会影响波动阻力和形式阻力的大小,应在数值模式的参数化方案中给予考虑.分析还表明,当地形坡度减到一定程度时,形式阻力可以忽略不计.
By solving the linearized atmospheric dynamic equation system including turbulent dissipation, the analytical solutions of wave drag and form drag over small scale terrain in a nocturnal stable boundary layer are obtained. The solutions show that the atmospheric conditions and terrain features such as the stability, wind speed and turbulent dissipation in the stable layer, the depth of the stable layer, the stability and wind speed in the upper residue layer as well as the height and slope of the terrain are all the factors affecting the values of the wave drag and form drag. These factors should be considered in the parameterization schemes of the wave drag and form drag in a numerical model. The analyses also show that the form drag may be omitted as long as the terrain slope is small to a certain degree.