(1) Institut für Kernphysik, Universität Kiel, 24118 Kiel, Germany;(2) CEA, Service d'Astrophysique, C.E. Saclay, 91191 Gif-sur-Yvette, France;(3) Instituto Fisica Cosmica del CNR, Universitá di Milano, 20133 Milano, Italy
Abstract:
Since June 1992 the Kiel Electron Telescope on board ULYSSES measures 26-day variations of the order of 6% in the fluxes of high energy H and He. In May 1993 ULYSSES entered into the unipolar region of the southern polar coronal hole, but continued to observe similar effects: increases in the MeV proton channels due to acceleration near the shocks of the corotating interaction region and decreases in the intensity of galactic nuclei associated with the same region. Amplitude variations are presented for different magnetic rigidities and the effects are discussed in view of corotating shock development in a 3-dimensional heliospheric structure.