HR: 1340h
AN: P43A-1025    [Abstracts]
TI: The solar wind upstream of Saturn – a comparison of pre- and post-SOI interplanetary magnetic field structure.
AU: * Jackman, C M
EM: c.jackman@imperial.ac.uk
AF: Imperial College London, Prince Consort Road, London, SW7 2BW, United Kingdom
AU: Forsyth, R J
EM: r.forsyth@imperial.ac.uk
AF: Imperial College London, Prince Consort Road, London, SW7 2BW, United Kingdom
AU: Dougherty, M K
EM: m.dougherty@imperial.ac.uk
AF: Imperial College London, Prince Consort Road, London, SW7 2BW, United Kingdom
AB: The interplanetary medium upstream of Saturn can have a very strong impact on magnetospheric dynamics. During the declining phase of the solar cycle, the heliosphere is highly structured by Corotating Interaction Regions (CIRs), while this pattern breaks down somewhat closer to solar minimum. We compare Cassini magnetometer data from the cruise to Saturn, and from a period after Saturn Orbit Insertion (SOI) where Cassini had a prolonged excursion into the solar wind. We present the predicted and observed values for the Parker Spiral angle over this long time interval upstream of Saturn and discuss the implications of this. The pre-SOI data encompass an interval where the solar wind was highly disturbed by the "Halloween Storms", a period of extreme solar activity during October/November 2003. The effects of these storms have been widely studied in the vicinity of the Earth, where some of the highest solar wind speeds ever were recorded. We examine how this unusual solar wind evolved by the time it reached Cassini, and discuss the expected magnetospheric response. This is then in turn contrasted with the more typical solar wind conditions, and solar cycle effects taken into account.
DE: 2100 INTERPLANETARY PHYSICS
DE: 2134 Interplanetary magnetic fields
DE: 2164 Solar wind plasma
DE: 2756 Planetary magnetospheres (5443, 5737, 6033)
DE: 2784 Solar wind/magnetosphere interactions
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting