[en] Jupiter's powerful aurorae are caused by energetic electrons precipitating from the magnetosphere into the atmosphere where they excite the molecular hydrogen. These electrons are characterized over the auroral regions by the Jovian Auroral Distributions Experiment (JADE) and the Jupiter Energetic particle Detector Instrument (JEDI) on Juno. Derived energy spectra and pitch angle distributions help us understand how these aurorae are created and powered. Corresponding ultraviolet emissions from reconstructed images taken by the Ultraviolet Spectrograph (UVS) on Juno give us the context and allow us to match the electron observations with their impact on the atmosphere. In this study, we show how the electron energy flux and characteristic energy vary from the polar region, over the main emission, and equatorward of the main emission in relationship with the UV emissions. We focus on the closest passes which range from 1.25 to 2 RJ. We find that while the >30 keV electrons dominate the energy flux in the polar regions and equatorward of the main emission, there is a region near the maximum UV brightness where: i) the characteristic energy decreases from more than 100 keV to less than 10 keV and ii) the maximum contribution to, or a significant fraction of, the total downward energy flux comes from <30 keV electrons. This pattern is present in all eight perijove passes for which JADE and JEDI have the best pitch angle coverage. <P />
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Allegrini, Frederic; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States ; Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas
Mauk, Barry; The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
Clark, George; The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
Gladstone, G. Randy; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States ; Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas
Hue, Vincent; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States
Kurth, William S.; University of Iowa, Iowa City, Iowa, USA
Bagenal, Fran; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, Colorado, USA
Bolton, Scott; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States
Bonfond, Bertrand ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Connerney, John E. P.; Space Research Corporation, Annapolis MD 21403, USA ; NASA Goddard Space Flight Center, Greenbelt MD 20771, USA
Ebert, Rob; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States ; Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, Texas
Greathouse, Thomas; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States
Imai, Masafumi; University of Iowa, Iowa City, Iowa, USA
Levin, Steven; Jet Propulsion Laboratory, Pasadena, California, USA
Louarn, Philippe; Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France
McComas, David J.; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States ; Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
Saur, Joachim; Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany
Szalay, Jamey; Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
Valek, Philip W.; Southwest Research Institute, Department of Space Science, San Antonio, Texas, United States
Wilson, Rob J.; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, Colorado, USA)