MERIDIONAL CIRCULATION IN THE THERMOSPHERE - 1. EQUINOX CONDITIONS.

Abstract

The mean meridional circulation and latitudinal variation of temperature in the thermosphere are considered for equinox conditions. With regard to these parameters there have been serious discrepancies between observational indications and theoretical expectations. A numerical model of the zonally symmetric thermospheric circulation is formulated and solved using a finite difference initial value approach to steady-state solutions. Solutions are obtained for three different prescriptions of forcing terms: solar heating alone, solar heating plus an effective momentum source due to diurnal variations, and inclusion of a high-latitude heat source representing Joule dissipation of electric current systems.