Increase in the count rates of ground-based cosmic-ray detectors caused by the heliomagnetic disturbance on 5 November 2023

Abstract

This letter presents a rare physical phenomenon associated with solar activity, manifesting in anomalies within neutron, electron, and gamma-ray fluxes in the atmosphere. Conventionally, Earth's magnetic field disturbances reduce cosmic ray intensity reaching the surface. However, a temporary surge in cosmic ray flux occurs intermittently known as the Magnetospheric Effect (ME). Our observations reveal that this effect predominantly induces a count rate increase in particle detectors positioned at middle latitudes on mountaintops. On November 5, 2023, a 2-3% increase in neutron monitors at mountain altitudes and up to 5% increase in thin plastic scintillators registering electrons and gamma rays. This flux escalation coincided with a southward orientation of the interplanetary magnetic field. Importantly, we present, for the first time, the energy spectrum of the Magnetospheric Effect observed at two mountaintops: Aragats and Zugspitze. Simulations of low-energy proton interactions in the terrestrial atmosphere affirm the augmentation of low-energy cosmic rays. Protons, typically restricted by the geomagnetic cutoff, reached the Earth's atmosphere, generating detectable particle showers on the Earth's surface.