Properties of the upper atmosphere and their relation to the radiation belts of the earth

Singer, S. Fred

doi:10.1016/0032-0633(60)90011-8

Cited by 9 publications

(1 citation statement)

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“…(~pik and Singer (1959(~pik and Singer ( , 1960(~pik and Singer ( , 1961 showed that the barometric formula cannot give the correct density distribution in the exosphere (see also Singer 1960a). Under the assumption that the exosphere is only populated by particles travelling upward from the barosphere and that these particles have a Maxwellian velocity distribution at the exobase, the partial number density of the ballistic re-entry component and the escaping particles were calculated separately.…”

Section: The Neutral Exosvherementioning

confidence: 99%

Exospheric models of the topside ionosphere

Lemaire

Schérer

1974

Space Sci Rev

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The historical evolution of the study of escape of light gases from planetary atmospheres is delineated, and the application of kinetic theory to the ionsphere is discussed. Ionospheric plasma becomes collisionless above the ion-exobase which is located near 1000 km altitude in the trough and polar regions, and which coincides with the plasmapause at lower latitudes. When the boundary conditions at conjugate points of a closed magnetic field line are different, interhemispheric particle fluxes exist from the high temperature point to the low temperature point, and from the point of larger concentrations to the point of smaller concentrations; therefore the charge separation electric field in the exosphere is no longer given by the Pannekoek-Rosseland field. For non-uniform number densities and temperatures at the exobase, the observed r-4 variation of the equatorial density distribution is recovered in the calculated density distributions. Taking account of plasmasheet particle precipitation does not change very much the electric field and ionospheric ion distributions, at least for reasonable densities and temperatures of the plasmasheet electrons and protons. For field aligned current densities along auroral field lines smaller than 10 -5 Am -~, the potential difference between the ion-exobase and plasmasheet is about --3V. In the case of open magnetic field lines the flow speed of hydrogen and helium ions in the exosphere becomes rapidly supersonic as a consequence of the upward directed charge separation electric field, whereas the oxygen ions have a negligible small bulk velocity. Adding a photoelectron etttux decreases the thermal electron escape but does not change significantly the number density distributions.

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Section: The Neutral Exosvherementioning

confidence: 99%