ORIGIN OF THE SOLAR-WIND FROM COMPOSITION DATA

The ESA/NASA spacecraft Ulysses is making, for the first time, direct measurements in the solar wind originating from virtually all places w here the corona expands. Since the initial two polar passes of Ulysses occur during relatively quiet solar conditions, we discuss here the t hree main regimes of quasi-stationary solar wind flow: the high speed streams (HSSTs) coming out of the polar coronal holes, the slow solar wind surrounding the HSSTs, and the streamers which occur at B-field r eversals, Comparisons between H-alpha maps and data taken by Ulysses d emonstrate that as a result of super-radial expansion, the HSSTs occup y a much larger solid angle than that derived from radial projections of coronal holes, Data obtained with SWICS-Ulysses confirm that the st rength of the FIP effect is much reduced in the HSSTs. The systematics in the variations of elemental abundances becomes particularly clear, if these are plotted against the time of ionisation (at the solar sur face) rather than against the first ionisation potential (FIP). We hav e used a superposed-epoch method to investigate the changes in solar w ind speed and composition measured during the 9-month period in 1992/9 3 when Ulysses regularly passed into and out of the southern HSST. We find that the patterns in the variations of the Mg/O and O7+/O6+ ratio s are virtually identical and that their transition from high to low v alues is very steep, Since the Mg/O ratio is controlled by the FIP eff ect and the O7+/O6+ ratio reflects the coronal temperature, this findi ng points to a connection between chromospheric and coronal conditions .