Energetic particles during the first two years of SOHO science mission

Abstract

Energetic particle intensities observed by ERNE instrument onboard SOHO spacecraft during the first two years of SOHO science mission have been analysed and compared to observations of IMP 8 satellite around two earlier sunspot minima. During an eight month period around the latest sunspot minimum, which occurred in October 1996, energetic particle intensities stayed at a lower level than during any equivalent period around solar minima of July 1976 and June 1986. During the period from March to October, 1996, there was not a single day, when the daily averaged intensity of 1.6-3 MeV protons exceeded the level of 1 proton/(cm ² sr s MeV). Also monthly counts of grouped solar flares and mean monthly sunspot number were lower than during minima of 1976 and 1986.