The influence of several atmospheric variables on cosmic ray muons observed by KACST detector

Abstract

In this study, the effects of atmospheric pressure and temperature on cosmic ray muons have been investigated using data recorded by the KACST detector (Riyadh, Saudi Arabia; Rc = 14.4 GV) for the beginning of the quiet periods of the 24th solar cycle. The muon data were, initially, correlated with the atmospheric pressure, and the desired coefficient was obtained and used to eliminate the pressure effect from the muon measurements. The pressure-corrected data are then analysed to study the effect of the atmospheric temperature on cosmic ray muons, using five methods. Four methods investigate the effect of the ground temperature, the atmospheric temperatures and atmospheric heights at several atmospheric levels, on the measured muon rate. In the fifth method, the muon data were correlated with the atmospheric weighted temperatures integrated up to different atmospheric heights. For all cases, the desired correction coefficients were obtained, and their variations at several atmospheric levels were studied. The obtained coefficients were then used to correct the cosmic ray data. We found that the atmospheric pressure effect shows the greatest differences between the corrected and uncorrected rate (up to 1%). Instead, corrections made to the muon data using the remainder of the considered parameters modify the muon rate by a small amount (less than 0.5%) compared to the uncorrected rate.