Electron precipitation and related aeronomy of the Jovian thermosphere and ionosphere

Journal Article · Mon Aug 01 04:00:00 EDT 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA088iA08p06143· OSTI ID:5667978

Waite, Jr, J H; Cravens, T E; Kozyra, J; Nagy, A F; Atreya, S K; Chen, R H

Voyager ultraviolet spectrometer (UVS) measurements provided the first unassailable evidence for particle precipitation in the Jovian atmosphere. Strong Lyman and Werner band emissions at high latitudes indicate particle precipitation energy fluxes of about 10 ergs cm/sup -2/ s/sup -1/. On the other hand dayglow Lyman and Werner emissions at mid- and low-latitudes may indicate additional particle precipitation fluxes on the order of 0.3 ergs cm/sup -2/ s/sup -1/ at all latitudes. Such particle precipitation can have signficant aernomical effects on the Jovian thermosphere and ionosphere. A one-dimensional theoretical model is used to study these effects for the case of electron precipitation, although ion precipitation produces similar effects. Diffusion equations are solved for all the major neutral species and for H/sup +/, and photochemical solutions are given for short lived ions. These and ionospheric components of the model are coupled with the electron and ion energy equations and a two-stream electron transport code that calculates the energy depostion of precipitating electrons (considered to be the precipitating particles) and photoelectrons. An independent calculation of the vertical neutral temperature is also obtained. The results of the model calculations can be broadly categorized as effects of electron precipitation (1) on the neutral composition and temperature of the thermosphere, and (2) on the composition and structure of the ionosphere. Auroral electron precipitation by 10-keV electrons with a total energy flux of 10 ergs cm/sup -2/ s/sup -1/ produces 4.7 x 10/sup 11/ H atoms cm/sup -2/ s/sup -1/ and 5 ergs cm/sup -2/ s/sup -1/ of heat, over 2 orders of magnitude larger than solar EUV processes that produce 3.3 x 10/sup 9/ H atoms cm/sup -2/ s/sup -1/ and 0.03 ergs cm/sup -2/ s/sup -1/ of heat.

• Research Organization: Space Science Laboratory, NASA Marshall Space Flight Center, Huntsville, Alabama 35812
• OSTI ID: 5667978
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 88:A8; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
CHARGED-PARTICLE PRECIPITATION
CHEMICAL COMPOSITION
EARTH ATMOSPHERE
ELECTRON PRECIPITATION
ION TEMPERATURE
IONIC COMPOSITION
JUPITER PLANET
PLANETARY IONOSPHERES
PLANETS
TEMPERATURE GRADIENTS
THERMOSPHERE