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Cassini UVIS observations of Jupiter's auroral variability

Central Arizona College, 8470 N. Overfield Road, Coolidge, AZ 85228, USA; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA; University of Southern California, Los Angeles, CA, USA; Jet Propulsion Laboratory, Pasadena, CA, USA; University of Iowa, Iowa City, IA, USA; University of Michigan, Ann Arbor, MI, USA; Southwest Research Institute, San Antonio, TX, USA; Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany; Boston University, Boston, MA, USA; University of Liege, Liege, Belgium; University College, London, UK; Received 12 October 2004. Revised 16 April 2005. Available online 24 August 2005.
Icarus, v.178, 312-326 (2005) DOI: 10.1016/j.icarus.2005.05.021
Source: OAI

ABSTRACT During the December 2000 Cassini flyby of Jupiter, the Cassini Ultraviolet Imaging Spectrograph observed episodic brightenings of the UV aurora caused by solar coronal mass ejections (CMEs). The integrated auroral output in the H2 band emissions increased by a factor of 3-4 in two major events, on days 280 and 325-326 of 2000. The CME events cause measurable changes in the solar wind that we are examining in search of triggers of the observed auroral brightening events. We have detrended the auroral data to remove the usual longitudinal variations in auroral output, making it easier to study the large events. This is done by using the auroral arc area observed at each central meridian longitude in HST images to create an expected lightcurve. Jupiter's auroral response to CME shocks is not as prompt as the terrestrial response, but both involve nearly simultaneous radio bursts and auroral emissions.

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