Novel Simulation Framework for Analyzing Cosmic Ray Particle Distributions at a Global Scale

Cosmic ray measurements have inspired numerous interesting applications over several decades worldwide. These applications encompass non-invasive cosmic ray muon tomography, which enables the imaging of concealed dense objects or structures, the monitoring of area-averaged soil moisture with cosmic ray neutrons in agriculture and climate studies, real-time monitoring of the dynamical changes of the space and earth weather, etc. The demand for a quantitative characterization of cosmic ray shower particles near the Earth's surface is substantial, as it provides realistic particle spectra and rates for these diverse applications. In this study, we introduce Earth Cosmic Ray Shower (ECRS), a GEANT4-based software designed to simulate cosmic ray particle interactions in the atmosphere. ECRS incorporates the U.S. Standard Atmospheric Model and integrates a time-dependent geomagnetic field based on the Tsyganenko and IGRF models. Additionally, we present two case studies illustrating variations in the location-dependent average particle energy for muons, electrons, neutrons, and gammas at sea level. An outlook of this project is provided toward the conclusion.