OBSERVATIONS OF GALACTIC COSMIC-RAYS AND THE ANOMALOUS HELIUM DURING ULYSSES PASSAGE FROM THE SOUTH TO THE NORTH SOLAR POLE

We compare observations of the modulated intensities and spectra of ga lactic cosmic ray nuclei and anomalous helium above 30 MeV/n measured by the COsmic and Solar Particle INvestigations (COSPIN) High Energy T elescope (HET) on Ulysses with similar observations from the IMP-8 ear th-orbiting satellite between September 1994 and August 1995. During t his interval Ulysses made a rapid scan of solar latitude from 80.22 de grees S latitude to 80.22 degrees N latitude at radial distances betwe en 2.2 and 1.3 AU in a period of slowly decreasing solar modulation. T he observations confirm our previous conclusions from measurements in the southern hemisphere that solar modulation is remarkably sphericall y symmetric in the inner heliosphere. Flux increased towards the poles by less than a factor of two for al species measured with no signific ant changes in the spectra of galactic cosmic ray nuclei and anomalous components. Fluxes over the north pole were in general slightly highe r (similar to 10-20%) than fluxes over the south pole. As reported by Simpson et al. (1996), the modulation was symmetrical about a surface at latitude 10 degrees S. At the boundaries of the equatorial zone def ined by low speed solar wind the solar wind speed increased by a facto r of two within 5 degrees of latitude with no effect on the modulated cosmic ray and anomalous component spectra. This suggests that typical cosmic ray trajectories are not tightly confined in heliographic lati tude and freely cross the boundary between the polar and equatorial zo nes during the modulation process. At the highest latitudes (> similar to 50 degrees from the symmetry surface at similar to 10 degrees S) l atitudinal gradients in the cosmic ray intensity were significantly sm aller than at lower latitudes.