Energetic Particles Measured in and out of the Ecliptic Plane During the Last Gnevyshev Gap

Abstract

We analyzed the temporal variation of energetic particles measured by the Low Energy Telescope (LET), the Kiel Electron Telescope (KET), and the High Energy Telescope (HET) instruments aboard Ulysses and the Electron Proton Helium Instrument (EPHIN) aboard SOHO during the last solar magnetic field polarity reversal in 2001. We have found two periods with anomalous low fluxes during that time that are present both at low and high heliolatitudes. We compared the energetic particle fluxes with solar energetic phenomena that traditionally have been associated with solar energetic particle (SEP) events at 1 AU. Our results show that these periods are related to relative minima in the number of X-ray flares and CMEs. Since Ulysses scanned the whole latitude range from 80 °S to 80 °N, we conclude that this process affects the inner three-dimensional heliosphere globally.