Results of the Ulysses fast latitude scan: Magnetic field observations

Abstract

The rapid crossing of the solar equatorial region by Ulysses as it returned from the south pole resulted in 7 crossings of the heliospheric current sheet between 10°S and 20°N and 10 distinct solar wind interaction regions between 18°S and 22°N. Both the extent of the current sheet and the latitude interval containing the interaction regions are a factor of ≈ 2 less than were observed by Ulysses when it left the equatorial region in 1993. A map of the current sheet in heliographic latitude and Carrington longitude reveals two folds corresponding to 4 magnetic sectors. The coronal holes associated with the sectors, the interaction regions and high-speed streams have been identified. Two sectors were associated with a pair of asymmetrically-placed polar coronal holes whereas the other two sectors coincided with a pair of near-equatorial coronal holes on opposite sides of the equator.