Numerical Modelling of the Stratosphere and Mesosphere

Abstract

The development of numerical models which can simulate the general circulation of the upper atmosphere with very high quantitative accuracy is a primary long range goal of much current research. Such models are needed to assess possible adverse effects of small changes in the concentrations of water vapor, aerosols, and photo-chemically active constituents in the upper atmosphere brought about by the proposed operation of large fleets of supersonic transports in the altitude range of 10–25 km. Clearly, models must be developed which can not only simulate the natural stratosphere with great fidelity, but which also can indicate the nature and range of naturally occurring variability—whether due to intrinsic instabilities in the upper atmosphere or to fluctuations in the tropospheric forcing—before it will be possible to make definitive calculations concerning man-made perturbations. Such a goal is unlikely to be realized without a precise understanding of the physical and dynamical processes which control all scales of motion in the upper atmosphere. In the previous chapter we have reviewed the role of linearized mechanistic models in the development of our understanding of the dynamics of large-scale motions in the stratosphere.