In-ecliptic CIR-associated energetic particle events and polar coronal hole structures: SOHO/COSTEP observations for the Whole Sun Month Campaign

The Solar and Heliospheric Observatory (SOHO), in halo orbit around the L1 Lagrangian point of the Sun-Earth system, combines a unique set of instrume nts for studies of the Sun and the heliosphere. SOHO's Comprehensive Suprat hermal and Energetic Particle Analyser measures in situ particles in the en ergy range 44 keV/particle to above 53 MeV/nucleon. For the time period of the Whole Sun Month Campaign in mid 1996 we have identified recurrent energ etic particle intensity increases in association with corotating interactio n regions (CIRs) in the energy range <10 MeV. Solar wind measurements of th e Wind spacecraft were used to estimate the corresponding magnetic source l ocation in Carrington longitude for comparison of energetic particles with synoptic maps of the lower corona, derived from images of SOHO's Extreme-ul traviolet Imaging Telescope, The comparison reveals a close relationship of latitudinal extensions of polar coronal holes, situated in regions up to 4 0 degrees away from the ecliptic, with CIR-associated in-ecliptic particle events.