大气潮汐的经典理论及有关现代模式的发展

按照历史发展, 回顾了从无耗无风背景下线性化的大气潮汐方程组出发得到一个二维定态变量可分离的基本偏微分方程及其全球Hough函数波模解的经典理论; 介绍了主要由Forbes和Hagan发展起来的在真实有耗有风背景下线性化的本质上仍是二维定态, 但纬度和高度变量不可分离的现代数值模式GSWM; 概述了近年来针对中高层大气的GCM (例如TIME-GCM, MUAM, CMAM和WACCM) 来研究潮汐非线性及非迁移潮汐等的发展趋势. 在融合理解的基础上对各模式的特点和模式间的差异进行了适当分析, 从中可以看出,半个世纪以来人们在从第一原理出发试图揭示全球大气潮汐的真实结构特征和长短期变化机制等方面进行了持续的努力, 这种努力又是与从利用地基雷达到卫星搭载仪器观测大气(特别是MLT区域的风场和温度场)的发展密不可分的. 

Classical Theory of Atmospheric Tides and Development of Some Related Modern Models

Roughly based on the historical order of advances in tidal theory, the classical theory that involves a 2D steady and variable separable basic partial differential equation, which is reduced from a set of starting equations linearized under an assumption without dissipations and background winds, and its global wave mode solutions expanded in Hough functions was reviewed at first. Then a modern numerical model (i.e., GSWM), which was mainly developed by Forbes and Hagan beginning from a linearization under realistic conditions of various dissipations and nonzero background winds and so is still 2D steady in essence but cannot be solved by the method of separation of the latitude and height variables, was introduced. At last, a developing tendency that people have begun in recent years to employ some GCM (e.g. TIME-GCM, MUAM, CMAM and WACCM), which pay more attentions to the middle and upper atmosphere, to study the tidal nonlinearity and nonmigrating tides etc. was summarized. Also given are some analyses about the characteristics of respective tidal models and differences between them by incorporating the understanding of the author. Along the way, it can be seen that during half a century starting from first principles people have made persistent efforts to disclose the realistic structural characteristics of the global atmospheric tides and the mechanisms for tidal long- and short-term variability, while this kind of endeavor is closely connected with the advances in observations of atmosphere especially the wind and temperature fields in the MLT by using from ground-based radars to instruments on board satellites.