The heliospheric magnetic field at solar minimum: Ulysses observations from pole to pole

The fast transit of the Ulysses spacecraft from the south polar regions of the heliosphere to the north polar regions has allowed us to obtain a unique perspective on the configuration and properties of the heliospheric magnetic field at a time of solar minimum activity. We compare the magnetic field in the northern and southern hemispheres and find no evidence of asymmetry in the radial component of the field or in the variances of the field. We find that the magnetic field polarity corresponds to that observed at the Sun. The only difference between the hemispheres is that, while magnetic field lines in the southern hemisphere have a most probable azimuth angle approximately 24◦ more tightly wound than predicted by the Parker model, those in the northern hemisphere are in good agreement with the model.