Saturn's equinoctial auroras

J. D. Nichols*, S. V. Badman, E. J. Bunce, J. T. Clarke, S. W. H. Cowley, F. J. Crary, M. K. Dougherty, J. C. Gérard, D. Grodent, K. C. Hansen, W. S. Kurth, D. G. Mitchell, W. R. Pryor, T. S. Stallard, D. L. Talboys, S. Wannawichian

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)

Abstract

[1] 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.
Original languageEnglish
Article numberL24102
Number of pages5
JournalGeophysical Research Letters
Volume36
Issue number24
Early online date23 Dec 2009
DOIs
Publication statusPublished - Dec 2009
Externally publishedYes

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