Abstract :
From Skylab, Helios and Ulysses observations we had learnt already how closely the 3D heliosphere is related to the underlying coronal structure. Around solar activity minimum, large polar coronal holes dominate the major part of the heliosphere, through the high-speed solar wind streams emanating from them. A different type of solar wind is restricted to a narrow near-equatorial belt (about 30 degrees in latitude). The magnetic topology is dominated by strong multipole components and multiple current sheets in the upper corona, and by a large-scale dipole field further outside, respectively. New observations by LASCO on SOHO cover both regions and may reveal clues to the processes responsible for the generation of the different types of solar wind.
