Planetary coronae and atmospheric evaporation

Galileo ultraviolet spectrometer observations of atomic hydrogen in the atmosphere of Ganymede

“…An exosphere is the region of planetary atmosphere where collisions between the neutral constituents essentially do not occur. The theory of the density distribution for a spherical atmosphere has been developed by Chamberlain [1963;Chamberlain and Hunten, 1987]. Figure 1 shows the result of an exosphere model fit to the Lyman alpha limb observations.…”

Hydrogen and deuterium loss from the terrestrial atmosphere: A quantitative assessment of nonthermal escape fluxes

“…The escape of hydrogen from the terrestrial atmosphere is an interesting and important problem because of its obvious relationship to the stability and evolution of the atmosphere [Chamberlain, 1963;Walker, 1977], its possible connection with the rise of oxygen in the atmosphere [Berkner and Marshall, 1965;Kasting, 1979], and its role in comparative planetology [Pollack and Yung, 1980 where bi is a binary collision parameter for molecular diffusion, Ha is the mean scale height of the atmosphere, and fi is the mixing ratio of total hydrogen (deuterium) at the homopause. From previous work we know that the limiting flux is attained by hydrogen.…”

“…Various nonthermal escape mechanisms have been studied extensively in the past two decades, and good reviews of some of the earlier ideas are given by Chamberlain [1963 Escape Velocity (cm s -1) for the 1974 AE-C orbits. This result is somewhat fortuitous, however.…”

Dependence of the charge exchange lifetimes on mirror latitude

“…The lifetimes calculated by Liemohn (1961) for the tens of keV ring current protons had been the primary theoretical source for comparing observational results with the charge exchange mechanism (Frank, 1967;Swisher and Frank, 1968;Russell and Thorne, 1970 Chamberlain, 1963), which has been used by Prolss (1973) in computing the proton lifetimes. The dependence of the charge exchange lifetimes on the mirror latitude for ions mirroring off the geomagnetic equator has not been re-examined in light of the improved hydrogen distribution models,and even the most recent articles (Tinsley, 1976;Lyons and Evans, 1976) in the literature still employ the approximation given by Liemohn (1961) under the assumption of the neutral hydrogen density model of Johnson and Fish (1960).…”

“…In this letter we use the Chamberlain (1963) model Opik and Singer, 1961) to provide the spatial distribution of the neutral hydrogen environment through which the ions traverse. This model appears to be in good agreement with recent Apollo 16 Lyman alpha imagery of the hydrogen geocorona (Carruthers, 1976) and Lyman alpha airglow measurements aboard several satellites (Meier and Mange,1970;Bertaux.and Blamont, 1973;Meier and Mange, 1973).…”