三维静力适应过程中声重力波的特性和能量转换研究
Study of characteristics of the acoustic gravity wave and energy conversion in the three-dimensional hydrostatic adjustment process
-
摘要: 为了研究三维静力适应过程的机理,推导三维静力适应方程组并导出声重力波的频散特征、解析解和能量转换关系以及位涡方程。结果表明,三维静力适应过程实际上就是三维声重力波和重力内波的频散过程,声重力波和重力内波的频率在水平方向上可以区分开来。声重力波的频率随着水平波数和垂直波数的增大而增大。取近轴近似,其解析解在空间上呈螺旋曲面,为大气中热通量和动量从一个区域向另一个区域的输送提供了一种机制,从而为研究大气提供了新的视角。垂直速度在动能与有效势能的转换、有效势能与有效弹性势能的转换中发挥着重要的作用,并且只发生在垂直方向上。在静力适应过程中总能量和位涡是守恒的。适应终态中有效势能比有效弹性势能大一个数量级。Abstract: In order to research the three-dimensional hydrostatic adjustment mechanism, the dispersion characteristics of acoustic gravity wave, analytical solutions and the energy conversion equation are deduced by the hydrostatic adjustment equations. The results show that the wave of controlling the hydrostatic adjustment process is the dispersion of acoustic gravity wave and internal gravity wave, and the acoustic gravity wave and the internal gravity wave are distinguished by the frequency of the horizontal direction. The frequency of acoustic gravity wave increases with the increasing horizontal and vertical wave number. Taking the paraxial approximation, analytical solutions of the hydrostatic adjustment process exist in the space spiral surface. It can provide an alternative mechanism for channeling heat and momentum from one region to another in the atmosphere and provide a new perspective to cutting edge research in meteorology. Vertical velocity plays an important role in the energy conversion. Conversions between the kinetic energy and the available potential energy, and between the available potential energy and the available elastic energy are only happen in the vertical direction. The hydrostatic adjustment process is in energy conservation and potential vorticity conservation. The magnitude of available potential energy is ten times bigger than that of the available elastic energy in the final equilibrium state.