ON DIURNAL VARIATION IN COSMIC-RAY INTENSITY AT OTTAWA

Abstract

Cosmic-ray data from a high pressure integrating ionization chamber, obtained at Ottawa, for 129 complete days during September 1950 to July 1951 are subjected to rigorous statistical analysis. The barometric coefficient is −0.19% per mm. of Hg for the period covered by this analysis. The results also indicate a physically significant 24-hr. wave in cosmic-ray intensity, with an amplitude of 0.12% of the total intensity, having its maximum at about 10.40 a.m. local mean time. The existence of the semidiurnal wave, however, is not physically significant.