Titre du document / Document title

Galileo orbiter ultraviolet observations of Jupiter aurora

Auteur(s) / Author(s)

AJELLO J. ⁽¹⁾ ; SHEMANSKY D. ⁽²⁾ ; PRYOR W. ⁽³⁾ ; TOBISKA K. ⁽⁴⁾ ; HORD C. ⁽³⁾ ; STEPHENS S. ⁽⁴⁾ ; STEWART I. ⁽³⁾ ; CLARKE J. ⁽⁵⁾ ; SIMMONS K. ⁽³⁾ ; MCCLINTOCK W. ⁽³⁾ ; BARTH C. ⁽³⁾ ; GEBBEN J. ⁽³⁾ ; MILLER D. ⁽³⁾ ; SANDEL B. ⁽⁶⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Jet Propulsion Laboratory, Califomia Institute of Technology, Pasadena, ETATS-UNIS
⁽²⁾ Department of Aerospace Engineering, University of Southern, California, Los Angeles, ETATS-UNIS
⁽³⁾ Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, ETATS-UNIS
⁽⁴⁾ Federal Data Corporation, Jet Propulsion Laboratory, Pasadena, California, ETATS-UNIS
⁽⁵⁾ Space Physics Research Laboratory, University of Michigan, Ann Arbor, ETATS-UNIS
⁽⁶⁾ Lunar and Planetary Laboratory, University of Arizona, Tucson, ETATS-UNIS

Résumé / Abstract

In 1996 during the first four orbits of the satellite tour the Galileo ultraviolet spectrometer (UVS) (11304320 A) and extreme ultraviolet spectrometer (EUVS) (540-1280 A) performed near-simultaneous observations of the Jupiter aurora in both the north and south polar regions. These observations are modeled to provide the absolute surface brightness of the aurora from the H₂ Rydberg Systems (B, B', B, C, D, D' → X band systems). The spectral distribution and brightness of the EUV aurora are sensitive to H₂ abundance, H₂ temperature, and CH₄ abundance. Analysis of the emission spectra indicates that the EUV aurora (800-1200 A) are produced over a range of altitudes corresponding to slant column abundances of H₂ from 10¹⁶ to 10²⁰ cm^-2 or greater. The UVS spectra of the far ultraviolet (FUV) from 1130 to 1700 A are optically thin in H₂, but highly sensitive to the CH₄ column abundance and to the secondary electron energy distribution. The slant column abundance of CH₄ absorbers found from models of the FUV spectra varied in the range 0 - 10 x 10¹⁶ cm^-2, indicating the presence of both high altitude aurora, at or above the homopause, and deep aurora. The FUV spectra show C₂H₂ absorption bands near 1520 A. The surface brightness of the aurora from the H₂ Rydberg Systems ranged from 100 to 600 kR and of H Lyman α was 60 to 130 kR for a 2000 km wide oval. The total power input to the atmosphere from particle deposition is estimated to be ∼ 1 X 10¹⁴ W.

Revue / Journal Title

Journal of geophysical research   ISSN 0148-0227 

Source / Source

Congrès
Conference on Magnetospheres of the Outer Planets, Boulder, Colorado , ETATS-UNIS (17/03/1997)
1998, vol. 103, n^o E9 (438 p.)  (1 p.1/4), pp. 20125-20148

Langue / Language

Anglais

Editeur / Publisher

American Geophysical Union, Washington, DC, ETATS-UNIS  (1949) (Revue)

Mots-clés anglais / English Keywords

Data analysis ; Modelling ; Brightness distribution ; Surface brightness ; Hydrogen Molecules ; Methane ; Column density ; Acetylene ; Absorption band ; Polar region ; Jupiter planet ; Planetary magnetospheres ; Aurorae ; Galileo space probes ; Extreme ultraviolet spectra ; Emission spectra ;

Mots-clés français / French Keywords

Analyse donnée ; Modélisation ; Distribution brillance ; Brillance surface ; Hydrogène Molécule ; Méthane ; Densité colonne ; Acétylène ; Bande absorption ; Zone polaire ; Planète Jupiter ; Magnétosphère planétaire ; Aurore ; Sonde spatiale Galileo ; Spectre UV extrême ; Spectre émission ;

Mots-clés espagnols / Spanish Keywords

Distribución brillantez ; Brillantez superficie ; Densidad columna ; Banda absorción ; Zona polar ;

Localisation / Location

INIST-CNRS, Cote INIST : 3144, 35400007054605.0230