The role of tidal and planetary waves in the middle atmosphere

Abstract

With interest in atmospheric science increasing in the last thirty years, the development of numerical models that simulate motion in the atmosphere has become invaluable. The Extended Canadian Middle Atmosphere Model, or extended CMAM, is the first such model to be developed in the entire world. As part of the development process, particular aspects of atmospheric motion are selected and data generated by the model is scrutinized to determine how well the motion is simulated. Here, the particular aspects of concentration are tidal and planetary waves. A basic description of atmospheric composition is given as well as an introduction to atmospheric dynamics. The theoretical framework of atmospheric waves and tidal motion is then developed from first principles, with emphasis placed upon prognostic rather than diagnostic equations. A description of the numerical methods utilized by the extended CMAM is specified as well as the physical process of obtaining and manipulating the data. The data analysis and results are divided into two sections: one concerning the tidal signatures produced by the model, and one concerning planetary waves. All of the computer programs employed for this task are attached as appendices.