Quantitative calculation of the charge-exchange-induced atomic hydrogen escape flux

The measurements of the ion and electron concentration and temperature from the ISIS 2 polar-orbiting spacecraft and from the Arecibo incoherent back-scatter radar along with the energy balance equation and assumption of diffusive equilibrium were used to construct ion and electron concentration and temperature profiles along magnetic field lines under equinox conditions. These plasmaspheric models were combined with neutral models to calculate the neutral hydrogen escape fluxes (F/sub ce/), due to charge exchange between hot thermal protons on one hand and atomic hydrogen and oxygen on the other, as a function of plasmaspheric position, time of day, and solar activity, F/sub ce/ was found to increase as the absolute value of the dipole latitute decreased, reaching its maximum value at the magnetic equator. At fifteen hours LT on March 23, 1972, F/sub ce/ at the magnetic equator was 3 x 108 atoms cm-2 s-1. On May 6, 1972, at Arecibo F/sub ce/ was found to vary from approximately 9 x 106 atoms cm-2 s-1 at four hours LT to about 2.5 x 106 atoms cm-2 s-1 at about eleven hours LT. The diurnal average value of F/sub ce/ at Arecibo on April 19, 1974 (F10.7 of 82) was 0.5 x 108 atoms cm-2 s-1, and on May 6, 1972 (F10.7 of 116), about 1.3 x 108 atoms cm-2 s-1; thus a sharp increase of F/sub ce/ with solar activity is seen for low to moderate solar activity. In addition, the contribution of charge exchange between protons and atomic oxygen to the total value of F/sub ce/, the variation of the production of escaping hydrogen with altitude, and the effect of the newly-created hot hydrogen upon the neutral temperature are discussed