HR: 0800h
AN: SH31A-1162    [Abstracts]
TI: Ulysses Observations of the Heliospheric Current Sheet at Solar Maximum.
AU: * Child, S R
EM: simon.child@imperial.ac.uk
AF: Imperial College London, The Blackett Laboratory, Imperial College, Prince Consort Road, , London, SW7 2BW United Kingdom
AU: Forsyth, R J
EM: r.forsyth@imperial.ac.uk
AF: Imperial College London, The Blackett Laboratory, Imperial College, Prince Consort Road, , London, SW7 2BW United Kingdom
AB: Since 1990, the Ulysses mission has studied the previously unexplored third dimension of the heliosphere from an elliptical orbit tilted at approximately 80\deg to the solar equatorial plane. Here we present an ongoing attempt to understand the topology of the heliospheric magnetic field through solar maximum by studying spacecraft observations of the heliospheric current sheet (HCS). The dataset studied (April 2000 - June 2002) is centred on aphelion, includes the solar maximum south and north polar passes, and extends either side back down to latitudes of 50\deg and 40\deg in the south and north, respectively. Encounters with the HCS by Ulysses are observed at all latitudes in the southern hemisphere and up to 67\deg in the north. For each encounter the local orientation of the HCS has been obtained using the minimum variance technique. The results show an increase in the spread of the north-south elevation angle of the orientations with increasing latitude, most pronounced at high ($>$50\deg) southern latitudes. The orientations are consistent with the single highly tilted HCS previously inferred from the latitudinal distribution of Ulysses encounters during the second orbit at solar maximum.
DE: 7524 Magnetic fields
DE: 7536 Solar activity cycle (2162)
DE: 2134 Interplanetary magnetic fields
DE: 2162 Solar cycle variations (7536)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting