Energetic proton observations at 1 and 5 AU 2. Rising phase of the solar cycle 23

The increasing level of solar activity at the end of 1997 coincides with th e observation of solar energetic particle (SEP) events by the Wind and Ulys ses spacecraft. The proximity of Ulysses to the ecliptic plane during this period allows us to study the effects of the solar activity at two differen t heliolongitudinal and heliocentric distances but at similar heliolatitude s. We identify the main transient proton enhancements seen by Wind and Ulys ses from October 1997 to the end of December 1998, We compare their charact eristics and suggest an interpretation in terms of their heliospheric locat ion, the activity occurring at the Sun, and the conditions for particle pro pagation between the Sun and both spacecraft. Whereas at 1 RU different SEP events can be associated with individual coronal mass ejections (CMEs), at 5 AU long-lasting SEP events are observed while a sequence of CMEs takes p lace at the Sun, Continuous injection of particles from traveling CME-drive n shocks, the effects of particle propagation along interplanetary magnetic field lines, acid the corotation of these field lines across the Ulysses l ocation are the main factors responsible for these long-lasting periods of high particle intensity observed by Ulysses.