LESIA - Observatoire de Paris

Planetary period oscillations at Saturn

Wednesday 21 November 2012, by Gabby Provan (Physics and Astronomy, University of Leicester, United Kingdom)

Tuesday 11 December 2012 à 11h00 , Lieu : Salle de conférence du bât. 17

Saturn’s magnetosphere chimes with oscillations at periods close to the planetary rotation period. The oscillatory period changes slowly over time [Galopeau and Lecacheux, 2000; Gurnett et al., 2005, Kurth et al., 2007, 2008], with slightly different periods being observed in the Northern and southern hemispheres [Gurnett et al., 2009a, Lamy, 2011]. Both periods are observed in the equatorial plane [Provan et al., 2011]. This talk aims to explore the periods, amplitudes and polarization of the magnetic field oscillations from 2004 and 2012. I will examine the relationship of these oscillations to the SKR, and show how these oscillations are related to the variations in the UV auroral power as observed by the Hubble spacecraft [Nichols et al., 2010a], the location of the UV auroral oval [Nichols et al., 2008,2010b, Provan et al., 2009], the position of the magnetopause and bow shock [Clarke et al., 2006, 2010a,b] and the vertical displacement and thickness of Saturn’s plasma sheet. Finally, I will examine how recent abrupt disruptions in the amplitudes of the magnetic oscillations may be related to the occurrence of Saturn’s Great White Spot.

0 | 10