Journal of Geophysical Research: Space Physics

Cover image for Vol. 122 Issue 7

Impact Factor: 3.426

ISI Journal Citation Reports © Ranking: 2014: 19/175 (Geosciences Multidisciplinary)

Online ISSN: 2169-9402

Associated Title(s): Journal of Geophysical Research

Small-scale structures observed in Saturn's aurora

Observations from the Ultraviolet Imaging Spectrograph Subsystem on NASA's Cassini spacecraft provide new detail on Saturn's aurora. The measurements, reported by Grodent et al. (2011), were made in August 2008 when the spacecraft was only 5 RS from the surface. They found two types of ultraviolet auroral substructures in the main ring of the emission-bunches of spots and narrow arcs-ranging in size from 500 km to several thousand kilometers. The researchers suggest that the small-scale structures are associated with magnetic-field-aligned electrical currents in Saturn's upper atmosphere that result from fluctuations in plasma flow triggered by Kelvin-Helmholtz waves in the magnetosphere. This is the first study to measure the small-scale structures in Saturn's ultraviolet aurora in detail and that provides insight into the dynamics of Saturn's magnetosphere.

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