Recombination Effects on Plasma Density Height Profile
Total ion (plasma) density as a function of the reduced 'height' h* (=h-200 km) related to Fig.18a (dashed curve, left ordinate); for comparison, the solid curve gives the density for a local ionization/recombination balance. The upward/downward flux asymmetry as resulting from the distributions functions in Fig.18a is represented by the long-short-dashed curve (right ordinate).
The curves are similar for actual ionospheric conditions (i.e. with the recombination coefficient one order of magnitude smaller and including elastic collisions) but the flux asymmetry is reduced to an average value of 5.5% as the distribution functions are much closer to a Maxwellian.