Solar cycle variations of GCR anisotropies at Ulysses

Abstract

The four telescope array of the EPAC investigation aboard Ulysses provides a good measurement of the anisotropy of the > 230 MeV GCR ux during those frequent time periods when MeV solar electrons are not present. We focused on the time period since late 1994 and found that the angular distribution of the GCR, as determined by the ratio of countrates in the four EPAC telescopes, re-mained essentially constant for more than three years.The angular distribution changed modestly but abruptly at the time of the large solar particle event of November 1997. A larger change began around Day 250 of 1999. At the same time the ACR intensity at Earth (both the interplanetary and geomagnetically trapped uences as measured by SAMPEX) was observed to decrease substan-tially. The rate of increase in the EPAC telescope ratios decreased but did not cease in 2000. These observations will be presented and discussed in the context of changes in the solar magnetic field configuration.