Energetic proton observations at 1 and 5 AU 1. January-September 1997

We present energetic particle observations by the Ulysses and Wind spacecra ft during the years 1997-1998. During this period, Ulysses moved from +19 d egrees to -19 degrees in heliographic latitude with heliocentric distances ranging from 4.71 to 5.41 AU. Wind was located near the Earth at 1 AU from the Sun in the ecliptic plane. The proximity of Ulysses to the ecliptic pla ne allows us to compare proton fluxes at different heliospheric distances a nd heliolongitudes but at similar latitudes, Enhancements in the energetic (approximately MeV) MeV proton fluxes were observed by both spacecraft in a close temporal association, We quantify this temporal coincidence and we d istinguish two time intervals based on the energy range of the proton flux increases and on the solar wind streams observed by the Ulysses spacecraft. Each one of these two periods (period 1, January-September 1997 and period 2, October 1997 to December 1998) corresponds also to a different level of solar activity. We establish a direct correspondence between individual pa rticle flux enhancements observed by both spacecraft throughout period 1, A t 1 AU the proton flux enhancements are associated with the occurrence of c oronal mass ejections (CMEs) at the Sun. At 5 AU the presence of high-speed solar wind streams, the contribution of energetic particles from CMEs, and the evolution of the magnetic field structures along which energetic parti cles propagate determine the final shape of the proton flux enhancements an d their time delays with respect to 1 AU. When a solar energetic particle ( SEP) event is observed at 1 AU, particle flux enhancements associated with recurrent high-speed solar wind streams at similar to 5 AU show a higher pa rticle flux intensity. We suggest that SEPs accelerated by CME-driven shock s act as a background seed particle population available to be reaccelerate d by shocks associated with corotating high-speed streams.