Influences of non-isothermal atmospheric backgrounds on variations of gravity wave parameters

因为在联合不同大气的区域的重力波浪(GW ) 的重要性，进一步的研究是必要的在非等温的气氛调查 GW 繁殖的特征。用一个非线性的数字模型，我们在不同非等温的气氛与各种各样的波长模仿小振幅 GW 的繁殖。我们的结果证明 GW 垂直波长在 stratopause 和中圈顶区域上面经历锋利的变化。明确地为有 5 km 的起始的垂直波长的 GW，在 50

Because of the importance of gravity waves （GWs） in coupling different atmospheric regions, further studies are necessary to investigate the characteristics of GW propagation in a non-isothermal atmosphere. Using a nonlinear numerical model, we simulate the propagation of small amplitude GWs with various wavelengths in different non-isothermal atmospheres. Our re- sults show that the GW vertical wavelength undergoes sharp changes above the stratopause and mesopause region. Specifically for a GW with an initial vertical wavelength of 5 km, the seasonal background temperature structure difference at 50° latitude can cause the vertical wavelength to vary by -2 krn in the mesosphere and by as large as -4.5 km in the lower thermosphere. In addition, the GW paths exhibit great divergence in the height range of -65-110 kin. Our results also show that the variations of GW path, vertical wavelength and horizontal phase velocity are not synchronized in a non-isothermal atmosphere as in an isothermal atmosphere. Despite the fact that all GWs change their characteristics as they propagate upward in a non-isothermal atmosphere, the variations relative to the initial parameters at a reference height are similar for different initial vertical wavelengths. Our results indicate that the changing characteristics of a gravity wave in a non-isothermal atmosphere need to be considered when investigating the relationship of GWs at two different heights.