Research on atmospheric gravity wave radiation from jet flows

本文对急流对大气重力波辐射的影响进行了数值模拟和理论研究。这一过程被称为“自发重力波辐射”，与经典的“地转调整”有着根本的区别。揭示了三个特点。(1)重力波是从接近平衡但不稳定的旋转流中自发辐射出来的。(2)只有当非定常旋转流的主导源的频率高于惯性频率（地球自转的影响）时，重力波才发生辐射和传播。(3)在简单的情况下，可以推导出远场重力波的解析估计，数值模拟结果也很好地验证了理论结果。此外，还提出了几种新的方法来分析巨大的气候模式数据，并显示了这些方法的有效性。

Numerical simulation and theoretical study of atmospheric gravity wave radiation from jet flows are done. The process is called as "spontaneous gravity wave radiation" and fundamentally different from the classical "geostrophic adjustment". Three features are revealed. (1) Gravity waves are spontaneously radiated from nearly balanced but unsteady rotational flows. (2) Only when the frequency of dominant source of unsteady rotational flows is higher than the inertial frequency (the effect of the Earth's rotation), gravity wave radiation and propagation occurs. (3) It is possible to derive analytical estimation for gravity waves at the far field in the simple situation, and theoretical results are well validated by the numerical simulation. In addition, several new methods to analyze huge climate model data are proposed and the effectiveness of those is shown.