Atmospheric Composition and Structure: Airglow and aurora; Magnetospheric Physics: Energetic particles: precipitating; Planetary Sciences: Solid Surface Planets: Aurorae and airglow; Space Plasma Physics: Kinetic and MHD theory; hot oxygen; escape
Abstract :
[en] The high-energy proton-hydrogen (H[SUP]+[/SUP]/H) beam associated with proton auroral precipitation transfers momentum in elastic and inelastic collisions with ambient thermal atomic oxygen in the high latitude thermosphere. This process provides a localized novel source of hot oxygen atoms in addition to exothermic photochemistry, charge exchange and momentum transfer from O[SUP]+[/SUP] ion precipitation and charge exchange with accelerated ionospheric O[SUP]+[/SUP] ions. We suggest that this source contributes to the population of the hot oxygen geocorona and to the flux of escaping oxygen atoms. For an incident proton energy flux of 1 mW m[SUP]-2[/SUP] and a mean energy E[SUB]mean[/SUB] ~ 5 keV, we calculate a density of hot oxygen atoms with energy above 1 eV of 2.0 × 10[SUP]3[/SUP] cm[SUP]-3[/SUP] and a mean kinetic energy of about 3.5 eV at 700 km. The total upward flux of hot oxygen atoms with energies higher 1 eV is estimated as 3.5 × 10[SUP]8[/SUP] cm[SUP]-2[/SUP] s[SUP]-1[/SUP].
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Shematovich, V. I.; Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia) ; AB(Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia) ; AC(Laboratoire de Physique Atmosphérique et Planétaire, Université de Liège, Liège, Belgium
Bisikalo, D. V.
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Language :
English
Title :
An auroral source of hot oxygen in the geocorona
Publication date :
01 January 2005
Journal title :
Geophysical Research Letters
ISSN :
0094-8276
eISSN :
1944-8007
Publisher :
American Geophysical Union, Washington, United States - District of Columbia
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