Empirical Modeling of the Geomagnetic Variation in the Thermosphere.

摘要

This paper briefly summarizes the development of empirical models of the geomagnetic variation in the thermosphere and exosphere. The earliest models were based exclusively on the results of satellite drag analysis. Although they present a much simplified picture of what is an extremely complex phenomenon, these models are still valid in many applications and remain in wide use. They do, however, leave much to be desired with respect to short-term accuracy and are quite inadequate in many cases in the way in which they depict local conditions. More recent observational data, particularly those from satellite-borne gas analyzers, have resulted in a considerable improvement in empirical models of the geomagnetic variation. One such model and its limitations are described in some detail. Some of the problems relating to the development of improved models in the future are also examined.