Some physical processes in the middle atmosphere

A review is made of the present status and significance of the various physical processes taking place in the middle atmosphere, in the context of the international Middle Atmosphere Program. The vital part played by ozone in the dynamics of the middle atmosphere is described. The dynamics of the region comprising the semi-annual, annual and quasi-biennial oscillations and the passage of wave disturbances like Kelvin and mixed Rossby-gravity waves are discussed. The spectacular event in the strato-mesosphere, viz. the warming is discussed in detail from both observational and dynamical points of view. Middle atmosphere plays a vital role in the linking of the solar activity signatures with weather phenomena. Hence an up-to-date account of the sun-weather relationships is given.