High latitude muon and neutron observation of the Forbush decrease during the May 2024 solar storms

A series of intense solar flares occurred in May 2024. Among other effects, a remarkable Forbush decrease in the cosmic ray flux was observed on the Earth. This event was recorded by muon and neutron monitoring systems located at Svalbard, a high-latitude site with minimal geomagnetic shielding. For this analysis we employed three scintillator-based muon telescopes of the Extreme Energy Events (EEE) project, 14 channels of a Bonner Sphere neutron Spectrometer (BSS), and thermal and epithermal neutron sensors used for hydrological monitoring, all installed at the international research site of Ny-Ålesund, 78.9ºN in the Svalbard archipelago. Most sensors showed significant responses and correlation during the event. The maximal magnitude of the Forbush decrease was estimated to be ~10-20% for thermal neutrons, ~8-15% for high-energy neutrons, and ~5% for muons. A correlation analysis of the time series provided by all these detectors during May 2024 was also performed, and is described in this contribution.