title: Field dipolarization in Saturn's magnetotail with planetward ion flows and energetic particle flow bursts: Evidence of quasi-steady reconnection.
abstract: We present a case study of an event from 20 August (day 232) of 2006, when the Cassini spacecraft was sampling the region near 32RSand 22 h LT in Saturn's magnetotail. Cassini observed a strong northward-to-southward turning of the magnetic field, which is interpreted as the signature of dipolarization of the field as seen by the spacecraft planetward of the reconnection X line. This event was accompanied by very rapid (up to ~1500 km s-1) thermal plasma flow toward the planet. At energies above 28 keV, energetic hydrogen and oxygen ion flow bursts were observed to stream planetward from a reconnection site downtail of the spacecraft. Meanwhile, a strong field-aligned beam of energetic hydrogen was also observed to stream tailward, likely from an ionospheric source. Saturn kilometric radiation emissions were stimulated shortly after the observation of the dipolarization. We discuss the field, plasma, energetic particle, and radio observations in the context of the impact this reconnection event had on global magnetospheric dynamics.
authors: School of Physics and Astronomy University of Southampton Southampton UK.
authors: C M
authors: CM
authors: Jackman
authors: Planetary Science Institute Tucson Arizona USA.
authors: M F
authors: MF
authors: Thomsen
authors: The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA.
authors: D G
authors: DG
authors: Mitchell
authors: Academy of Athens Athens Greece.
authors: N
authors: N
authors: Sergis
authors: Department of Physics Lancaster University Bailrigg UK.
authors: C S
authors: CS
authors: Arridge
authors: Department of Physics Lancaster University Bailrigg UK; Mullard Space Science Laboratory University College London Surrey UK; The Centre for Planetary Sciences at UCL/Birkbeck London UK.
authors: M
authors: M
authors: Felici
authors: Department of Physics Lancaster University Bailrigg UK.
authors: S V
authors: SV
authors: Badman
authors: The Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA.
authors: C
authors: C
authors: Paranicas
authors: Atmospheric, Oceanic and Space Sciences University of Michigan Ann Arbor Michigan USA.
authors: X
authors: X
authors: Jia
authors: Department of Physics and Astronomy University of Iowa Iowa City Iowa USA.
authors: G B
authors: GB
authors: Hospodarksy
authors: Space Research Institute Austrian Academy of Sciences Graz Austria.
authors: M
authors: M
authors: Andriopoulou
authors: Institute of Geophysics and Planetary Physics University of California Los Angeles California USA.
authors: K K
authors: KK
authors: Khurana
authors: School of Physics and Astronomy University of Southampton Southampton UK.
authors: A W
authors: AW
authors: Smith
authors: Blackett Laboratory Imperial College London London UK.
authors: M K
authors: MK
authors: Dougherty
keywords: Saturn; beams; magnetotail; reconnection