Evolution of cosmic ray fluxes during the rising phase of solar cycle 23: ULYSSES EPAC observations
B. Heber, E.Keppler
Max-Planck-Institut f"ur Aeronomie, Max-Planck-Str. 2, Katlenburg-Lindau, 37191, Germany
J.B. Blake
The Aerosspace Corporation, Los Angeles, CA 90009, USA
M. Fr"anz
Queen Mary & Westfield College, Astronomy Unit, London E1 4NS, UK
Galactic cosmic rays are entering the heliosphere from the interstellar medium, while anomalous cosmic rays are believed to be pickup ions accelerated at the heliospheric termination shock. Both particle species are modulated by the solar wind and the heliospheric magnetic field. Since 1997 solar activity increased and as a consequence the flux of galactic and anomalous cosmic ray decreased. In this paper we will discuss the variation of low energy anomalous cosmic rays as measured by the Ulysses Energetic Particle Composition Experiment (EPAC) on board Ulysses. Specifically we are addressing the question: Are there differences in the modulation of galactic cosmic rays and what are possible implication for the modulation of cosmic rays in the heliosphere?