Resolution of the discrepancy between Balmer α emission rates, the solar Lyman β flux, and models of geocoronal hydrogen concentration

Abstract

New satellite Balmer α measurements and solar Lyman β flux and line profile measurements, together with new measurements of the zodiacal light intensity used in correcting both ground and satellite Balmer α measurements for the effects of the Fraunhofer line in the zodiacal light, have been used in a reevaluation of the long-standing discrepancy between ground-based Balmer α emission rate and other geocoronal hydrogen parameters. The solar Lyman β line center flux is found to be (4.1 ± 1.3) × 109 photons cm−2 s−1 Å−1 at S10.7 = 110 and, together with a current hydrogen model which has 9.2 × 104 atoms cm−3 at 650 km for T∞ = 950 K, gives good agreement between calculated Balmer α emission rates and the ground-based and satellite measurements.