Observations of F-region vertical velocities at Millstone Hill 3. Determination of altitude distribution of H

摘要

Measurements of the vertical flux of 0+ in the F region have been made by the incoherent scatter technique at Millstone Hill. In part 2 of this paper, evidence was presented for the existence of fluxes of ≥ 10 cm sec into the protonosphere during the day. In this paper we employ the altitude variation of the O flux to infer the magnitude of the proton flux in the charge-transition region. Based on continuity considerations and the theory of minor ion diffusion in the topside of the F layer, we have attempted to determine the abundance of H in the altitude interval where it is a minor ion. The results indicate that the abundance of neutral hydrogen near 600 km must exceed about 10 cm. However, the absence of detectable amounts of H in the signal spectra taken near 1000 km indicates that the transition altitude must be above 1000 km and in turn the neutral-hydrogen abundance cannot exceed this estimate by more than a factor of 3.