Multi-point observations of CIR-associated energetic particles during the 2008 solar minimum

Between February 2008 and February 2009 solar activity remained very low, providing an excellent opportunity for multi-point studies of CIRs combining observations from STEREO and near-Earth spacecraft. In-situ energetic particle and plasma data from STEREO and ACE were ballistically mapped back to the Sun and compared. The observations were also correlated with remote-sensing observations of the parent coronal holes and synoptic maps of the coronal magnetic field. We found telltale discrepancies in the structures observed by different spacecraft which can not always be explained by the heliographic latitudinal separation between the spacecraft. The observations suggest that temporal evolution of the parent coronal holes as well as the interaction between CIRs and transient solar wind structures in the interplanetary medium also play an important role structuring the inner heliosphere.