Planetology: Fluid Planets: Atmospheres-composition and chemistry; Atmospheric Composition and Structure: Airglow and aurora; Atmospheric Composition and Structure: Thermosphere-composition and chemistry; Planetology: Fluid Planets: Interactions with particles and fields
Abstract :
[en] The energy distribution functions of nonthermal thermospheric hydrogen atoms are calculated for electron and proton precipitation in the Jovian aurora. A numerical model taking into account the production, elastic and inelastic relaxation and transport processes for hot H atoms is developed. This model is based on a Monte Carlo solution of the nonlinear Boltzmann equation for hot H atoms produced by electron and proton impact on H and H[SUB]2[/SUB] and exothermic chemical reactions. The distribution functions show a much higher energy tail for proton than electron precipitation. It is shown that the steady state flux of hot atoms (E>=2 eV) is essentially isotropic. The peak and column hot H densities are about 3×10[SUP]5[/SUP] cm[SUP]-3[/SUP] and 1×10[SUP]14[/SUP] cm[SUP]-3[/SUP] for a 100 erg cm[SUP]-2[/SUP]s[SUP]-1[/SUP] precipitation combining hard (22 keV) and soft (0.2 keV) electrons mixed with a 10 erg cm[SUP]-2[/SUP]s[SUP]-1[/SUP] flux of soft (0.3 keV) protons. These column densities, coupled with the wide range of hot H atom energies, may play an important role in the formation of the Lyman alpha line profile. Multiple scattering in the wings of the Ly alpha line by the fast H atoms is shown to partly account for the broad Ly alpha profile observed in the Jovian aurora with the Hubble space telescope.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Bisikalo, D. V.
Shematovich, V. I.
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Gladstone, G. R.
Waite, J. H.
Language :
English
Title :
The distribution of hot hydrogen atoms produced by electron and proton precipitation in the Jovian aurora
Publication date :
01 September 1996
Journal title :
Journal of Geophysical Research
ISSN :
0148-0227
eISSN :
2156-2202
Publisher :
American Geophysical Union (AGU), Washington, United States - District of Columbia
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
Ajello, J.M., D. Shemansky, T.L. Kwok, and Y.L. Yung, Studies of extreme-ultraviolet emission from Rydberg series of H2 by electron impact, Phys. Rev. A, 29, 636, 1984.
Ajello, J.M., S.M. Ahmed, I. Kanik, and R. Multari, Kinetic energy distribution of H(2p) from dissociative excitation of H2, Phys. Rev. Lett., 75, 3261, 1995a.
Ajello, J.M., I. Kanik, S.M. Ahmed, and J.T. Clarke, Line profile of H Lyman α from dissociative excitation of H2 with application to Jupiter, J. Geophys. Res., 100, 26,411, 1995b.
Allison, A.C., and J.F. Smith, Transport properties of atomic hydrogen, Atomic Data, 3, 317, 1971.
Bhardwaj, A., and R.P. Singhal, Optically thin H Lyman alpha production on outer planets: Low-energy proton acceleration in parallel electric fields and neutral H atom precipitation form ring current, J. Geophys. Res., 98, 9473, 1993.
Bisikalo, D.V., V.I. Shematovich, and J.C. Gérard, A kinetic model of the formation of the hot oxygen geocorona, II, Disturbed geomagnetic conditions, J. Geophys. Res., 100, 3715, 1995.
Broadfoot, A.L., et al., Extreme ultraviolet observations from Voyager 1 encounter with Jupiter, Science, 204, 979, 1979.
Broadfoot, A.L., et al., Ultraviolet spectrometer observations of Uranus, Science, 233, 74, 1986.
Clarke, J.T., H.W. Moos, S.K. Atreya and A.L. Lane, Observations from earth orbit and variability of the polar aurora on Jupiter, Astrophys. J., 241, L178, 1980.
Clarke, J.T., J. Trauger, and J.H. Waite, Doppler shifted H Ly α emission from Jupiter's aurora, Geophys. Res. Lett., 16, 587, 1989.
Clarke, J.T., L. Ben Jaffel, A. Vidal-Madjar, G.R. Gladstone, J.H. Waite, R. Prangé, J.C. Gérard, J. Ajello, and G. James, Hubble space telescope Goddard high-resolution spectrograph H2 rotational spectra of Jupiter's aurora, Astrophys. J., 430, L73, 1994.
Similar publications
Sorry the service is unavailable at the moment. Please try again later.
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.