Ulysses Observations at Solar Maximum: Introduction

Abstract

Observations during Ulysses' second solar orbit reveal basic changes between solar minimum and maximum. Fast high latitude wind disappeared in the southern hemisphere allowing slow wind to expand to all latitudes. In the north polar cap, both fast wind and a polar coronal hole were present. The magnetic field polarity reversal was detected in the north polar cap. The source dipole of the heliospheric magnetic field had a nearly equatorial, rather than an axial, orientation. Coronal mass ejections occurred at all latitudes including fast wind from the polar cap. Analysis of magnetic clouds confirmed their close association with solar filaments. The electron‐proton ratio of galactic cosmic rays changed at the magnetic polarity reversal. Solar Energetic Particles were present at all latitudes including the formation of particle “reservoirs” that require access to all latitudes and longitudes. Reservoir particles are also present at solar minimum at low flux levels.