Simultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora: Comparing emissions from H, H2 and H3+ at a high spatial resolution
English
Melin, H.[Space Environment Technologies, Los Angeles, California, USA); AB(Department of Physics and Astronomy, University of Leicester, Leicester, UK); AC(Department of Physics and Astronomy, University College London, London, UK); AD(Institut d'Astrophysique et de Géophysique, University of Liege, Liege, Belgium); AE(Department of Physics, Imperial College London, London, UK); AF(Institute of Space and Astronautical Science, JAXA, Sagamihara, Japan); AG(Central Arizona College, Coolidge, Arizona, USA); AH(Department of Physics and Astronomy, University of Leicester, Leicester, UK); AI(Department of Planetary Sciences, University of Arizona, Tucson, Arizona, USA); AJ(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA)]
Gustin, Jacques[Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Physique des atmosphères et des environnements planétaires >]
[en] Here, for the first time, temporally coincident and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. Ultraviolet auroral H and H[SUB]2[/SUB] emissions from UVIS are compared to infrared H[SUB]3[/SUB][SUP]+[/SUP] emission from VIMS. The auroral emission is structured into three arcs - H, H[SUB]2[/SUB] and H[SUB]3[/SUB][SUP]+[/SUP] are morphologically identical in the bright main auroral oval (˜73°S), but there is an equatorward arc that is seen predominantly in H (˜70°S), and a poleward arc (˜74°S) that is seen mainly in H[SUB]2[/SUB] and H[SUB]3[/SUB][SUP]+[/SUP]. These observations indicate that, for the main auroral oval, UV emission is a good proxy for the infrared H[SUB]3[/SUB][SUP]+[/SUP] morphology (and vice versa), but for emission either poleward or equatorward this is no longer true. Hence, simultaneous UV/IR observations are crucial for completing the picture of how the atmosphere interacts with the magnetosphere.
[Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Physique des atmosphères et des environnements planétaires >]
