非线性效应对重力波特性的影响

通过分析二维情况下重力波波包在等温大气中非线性传播的数值模拟结果，对非线性效应对重力波特性的影响做了定量分析。分析结果表明；重力波在非线性传播过程中，一方面由于非线性作用，随着波振幅的增加，垂直波长减小，同时平流成份增加；另一方面，尽管存在非线性效应，线性重力波的色散关系与偏振关系仍然适用。

EFFECTS OF NONLINEARITY ON THE CHARACTERISTICS OF GRAVITY WAVES

By analyzing the numerical results of nonlinear propagation of a Gaussiangravity-wave-packet in isothermal atmosphere, the effects of nonlinearity on thecharacteristics of gravity waves are studied quantitatively. The analyses show that:during the nonlinear propagation of gravity-wave--packet, affected by nonlinearity,the vertical wavelength show a decrease and the mean flow show clear enhancement.On the other hand, though there exists nonlinear effects, the linear dispersion relation and polarization are still feasible, which indicates that the dispersion relationand polarization based on linear gravity wave theory can be applied extensively innonlinear cases.