High Energy Cosmic Ray Modulation in March-June 1991

Abstract : The lowest galactic cosmic ray intensity since the initiation of continuous neutron monitor measurements was recorded in June 1991. Using neutron monitors and both surface and underground muon detectors we show that the solar- terrestrial phenomena between March and June 1 991 modulated the galactic cosmic ray intensity above 45 GeV. Cosmic trays, Neutron monitors, Muon detectors, Solar activity, Cosmic ray modulation.