Latitude dependent cosmic ray measurements using a cosmic watch detector

Abstract

Understanding how cosmic ray flux varies with geomagnetic latitude and atmospheric conditions is not only fundamental to space weather research but also offers an engaging entry point for education in astroparticle physics. In this study, we deployed the compact, low-cost Cosmic Watch muon detector—developed for educational use—aboard the South Korean icebreaker ARAON during two major voyages: the Antarctic expedition (Dec 2023—Apr 2024) and the Arctic expedition (Jul—Sep 2024). Operated alongside the semi-leaded Changvan neutron monitor, the Cosmic Watch successfully recorded muon count rates showing clear dependence on geomagnetic cutoff rigidity. Environmental data such as barometric pressure were also used to demonstrate the real-world complexity of particle detection. These results confirm the detector’s scientific viability under extreme conditions and its strong potential as a hands-on educational tool for students and citizen scientists exploring cosmic ray phenomena—as demonstrated by high school students from Mahidol Wittayanusorn School, Thailand.