Saturn's equinoctial auroras

Nichols, J. D. and Badman, S. V. and Bunce, E. J. and Clarke, J. T. and Cowley, S. W. H. and Crary, F. J. and Dougherty, M. K. and Gérard, J.-c. and Grodent, D. and Hansen, K. C. and Kurth, W. S. and Mitchell, D. G. and Pryor, W. R. and Stallard, T. S. and Talboys, D. L. and Wannawichian, S. (2009) Saturn's equinoctial auroras. Geophysical Research Letters, 36 (24): L24102. ISSN 0094-8276

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We present the first images of Saturn's conjugate equinoctial auroras, obtained in early 2009 using the Hubble Space Telescope. We show that the radius of the northern auroral oval is ∼1.5° smaller than the southern, indicating that Saturn's polar ionospheric magnetic field, measured for the first time in the ionosphere, is ∼17% larger in the north than the south. Despite this, the total emitted UV power is on average ∼17% larger in the north than the south, suggesting that field-aligned currents (FACs) are responsible for the emission. Finally, we show that individual auroral features can exhibit distinct hemispheric asymmetries. These observations will provide important context for Cassini observations as Saturn moves from southern to northern summer.

Item Type:
Journal Article
Journal or Publication Title:
Geophysical Research Letters
Additional Information:
Copyright 2009 by the American Geophysical Union.
Uncontrolled Keywords:
?? saturnaurorasconjugategeophysicsearth and planetary sciences(all) ??
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Deposited On:
11 Oct 2013 08:36
Last Modified:
18 Dec 2023 01:22