Journal of Geophysical Research Atmospheres · 1982 · 84 citations · 42 references
Natural SciencesAstronomyAtmospheric SciencePlanetary AstronomyPlanetary ScienceAtmospheric IonizationPlanetary AtmospheresSolar AtmosphereAuroral PhysicsEnergy DepositionEuv EmissionHydrogen ProductionIonizationSecondary Electron EmissionSecondary Electron ProductionThermospheric Heating
The study presents a model of how precipitating electrons interact with hydrogen atmospheres. The model uses the continuous slowing down approximation to compute degraded electron energy distributions and altitude profiles of ionization and H and EUV H₂ emissions for four incident electron spectra. The model predicts a total EUV H₂ emission efficiency of 10.6 kR per incident erg cm⁻² s⁻¹, an incident energy flux of ~8 ergs cm⁻² s⁻¹ at Jupiter, thermospheric heating rates of ~4 ergs cm⁻² s⁻¹ for Jupiter and ~0.1 ergs cm⁻² s⁻¹ for Saturn, and a globally averaged Jovian atomic hydrogen production rate of ~1×10¹⁰ atoms cm⁻² s⁻¹, far exceeding solar EUV dissociation.
A model of the interaction between incident electron precipitation and H 2 atmospheres is described. The local degraded primary and secondary electron energy distributions are calculated by using the continuous slowing down approximation. The altitude distribution of the ionization rate and various H and EUV H 2 emissions are calculated for four different incident electron spectra. A total EUV H 2 emission efficiency of 10.6 kR/incident erg cm −2 s −1 is obtained for a pure H 2 atmosphere. Comparison with the Voyager Jupiter observations indicates that an incident energy flux of about 8 ergs cm −2 s −1 was present at the time of the encounter if the emission is located in an H 2 ‐dominated region. The local thermospheric heating rate was about 4 ergs cm −2 s −1 for Jupiter and of the order of 0.1 erg cm −2 s −1 for Saturn. A globally averaged atomic hydrogen production rate of ∼1×10 10 atoms/cm² s −1 is induced by the Jovian auroral electron precipitation, largely exceeding the solar EUV dissociation rate.
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Extreme Ultraviolet Observations from Voyager 1 Encounter with Jupiter
A. L. Broadfoot, M. J. S. Belton, Peter Z. Takacs et al. · Science · 1979 · 758 citations
Natural Sciences, Astronomy, Physics +17
Extreme Ultraviolet Observations from Voyager 1 Encounter with Saturn
A. L. Broadfoot, B. R. Sandel, D. E. Shemansky et al. · Science · 1981 · 439 citations
Natural Sciences, Astronomy, Physics +14