Periodic tilting of Saturn's plasma sheet

Abstract

[1] From the vantage of the dawn sector, the INCA instrument on Cassini imaged neutral hydrogen atoms (20-50 keV) emitted from the center of the Saturn's plasma sheet for five days during late 2004. Points along the center of the plasma sheet were found from contoured images projected onto the noon-midnight plane; points within 20 Rs of Saturn were fitted to straight lines, and the slopes of these lines were examined as a function of time at one hour resolution. The slopes vary between ∼17° and ∼24° with a period of 10.80 hours, the same as that of Saturn kilometric radiation (SKR). This periodic tilting of the plasma sheet is in phase with SKR radiation in the sense that the maximum tilt angle occurs when the maximum in the SKR power occurs, and the tilt angle periodicity has a phase angle of ∼47° in SLS-3 longitude. Copyright 2008 by the American Geophysical Union.