KET Ulysses Observations of Sep in and Out of the Ecliptic

Abstract

Observations of eight solar energetic particle (SEP) events in the polar heliospheric regions and six events near the Jupiter orbit and their implications for the current paradigm of particle acceleration and propagation in the heliosphere are discussed. These events are casily identified with well-known episodes of the solar activity in 1992, 1997, 2000-2001 and 2003 and the corresponding SEP events near the Earth. Absolute intensities, fluences and propagation times of >30 MeV solar protons obtained from data of the Kiel Electron Telescope aboard the Ulysses spacecraft are compared with results of the GOES proton detector near the Earth. Analyzing the diversity and similarity of SEP events observed in different points of the heliosphere we conclude that the Sun should be a source of SEPs prolonged in space and time, much more complex than assumed before. Contrary, the global process of particle propagation in the heliosphere - along and cross-field diffusion - appears amazingly constant during the first 2-3 days since the particle release before the arrival of solar wind disturbances to the spacecraft. During the decay phase, when spatial gradients are weak or non-existing in the heliosphere (the reservoir effect), the events are different from each other, possibly reflecting the total number of particles injected into the heliosphere and the rate of particle escape from the storage region.