Empirical modeling of the thermosphere: An overview

A summary is given of thermospheric density modeling history and standard atmospheres. In particular, the approaches of the Jacchia and MSIS models were compared and contrasted. It was concluded that the Jacchia models are best if drag is the primary concern. MSIS is superior for variations in composition and temperature variations and comparison with theoretical models is facilitated by the use of spherical harmonics, which also provide a simple and consistent way of obtaining simplifications. Advantages and disadvantages of both models are listed and discussed.