Premium
Simultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora: Comparing emissions from H, H 2 and H 3 + at a high spatial resolution
Author(s) -
Melin H.,
Stallard T.,
Miller S.,
Gustin J.,
Galand M.,
Badman S. V.,
Pryor W. R.,
O'Donoghue J.,
Brown R. H.,
Baines K. H.
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048457
Subject(s) - magnetosphere , saturn , ultraviolet , physics , atmosphere (unit) , infrared , ion , astrophysics , astrobiology , astronomy , atmospheric sciences , geology , planet , meteorology , plasma , optics , quantum mechanics
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 2 emissions from UVIS are compared to infrared H 3 + emission from VIMS. The auroral emission is structured into three arcs – H, H 2 and H 3 + 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 2 and H 3 + . These observations indicate that, for the main auroral oval, UV emission is a good proxy for the infrared H 3 + 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.