A COSMIC RAY INCREASE RELATED TO SOLAR ACTIVITY

Abstract

An increase in the intensity of cosmic ray particles of minimum momentum at Ottawa, Canada, of 4.5 × 109 ev/c was observed with telescopes of solid angles 11.5 × 10−4 and 26.0 × 10−4 steradians with increase of solar activity. A large increase in cosmic ray activity for the period September 1956 to February 1957 was observed to accompany a large and sustained increase in solar activity as determined by means of the critical frequency of the F-2 layer.