Cosmic Ray Measurements made during the Cruise of H.M.A.S. Wyatt Earp 1947-48

Abstract

This paper describes the cosmic ray equipment used and the results obtained on the cruise of the Wyatt Earp between Melbourne, Australia, and the Antarctic Continent during the early part of 1948. Measurements of the total cosmic radiation over a narrow solid angle, the meson content over the same angle, and the total content over the full hemisphere were made. The difficulty of carrying out multiple correlations, when the independent variables are closely related, is discussed. The final correlation results show barometric coefficients of -0.144 per cent. per millibar (mb.) for the narrow angle total radiation, -0.114 for the meson content, and -0.192 for the total wide angle record. Long term temperature coefficients of -0.063 per cent. per degree C., -0.051 per cent. per degree C., and -0.012 per cent. per degree C., respectively, are obtained. The need to separate the daily and long-term temperature coefficients in regions where continental climates exist is shown. Daily temperature coefficients of 0.14 per cent. per degree C., 0.24 per cent. per degree C., and 0.16 per cent, per degree C. are obtained. It is found that no measurable latitude effect remains after pressure and temperature corrections have been made. The ratios of the total to meson content and the narrow angle intensity to wide angle intensity are independent of latitude south of Melbourne. A possible effect due to a magnetic disturbance on February 15 is noted, but later more severe storms did not produce any noticeable result. The results obtained are compared with those of other workers.