Abstract :
Observations from Skylab, Helios, Ulysses, and SOHO have demonstrated how closely the 3D heliosphere is related to the underlying coronal structure. Around solar activity minimum, the large polar coronal holes dominate the major part of the heliosphere, through the high-speed solar wind streams emanating from them. A distinctively different type of solar wind is restricted to a narrow near-equatorial belt (about 300 in latitude). Its magnetic topology is dominated by strong multipole components and multiple current sheets. Owing to the new telescopes on SOHO, various effects of CME disturbances propagating through the heliosphere can now be observed in much greater detail: optically from the photosphere out to 32 Rs, and later on by in situ spacecraft. It appears that the prediction reliability of space weather at Earthʹs orbit can be raised substantially in the near future.
