The Asymptotic Directions of Approach and the Magnetic Rigidity Cutoff of Cosmic Ray Particles for Airports at Different Latitudes and Longitudes

The calculation of asymptotic directions of approach of cosmic ray particles is an important tool in the determination of the rigidity cutoff for a given geographical site. We present the results of computations of the asymptotic latitude and asymptotic longitude and the magnetic rigidity cutoff for the eight airports (Apatity, Oulu, Warsaw, Lae, Buenos Aires Wellington and Mc Murdo) located at different latitudes and longitudes based on the numerical integration of equations of motion of charged particles of cosmic radiation in the Earth’s magnetic field. The initial distance from the center of the Earth was taken as 20 km above the surface. At about this altitude, most cosmic rays undergo nuclear collisions. Calculations were made for the model of the International Geomagnetic Reference Field (IGRF) in 2015.