Correlation Study on Ground-Based Neutron CountsBased on the ForbushDecrease Event of May 10, 2024

On May 10, 2024, the Earth’s magnetosphere experienced the strongest geomagnetic storm in nearly two decades, accompanied by a significant Forbush decrease (FD) event. In this study, we collected 10-minute interval neutron count variation data from the global ground-based neutron monitor network in May 2024, which had undergone dual corrections for atmospheric pressure and detection efficiency. A rational function model was employed to fit and analyze the data, yielding the temporal structure of the FD event. Furthermore, a correlation analysis was conducted between this temporal structure and the geographical information parameters of the ground-based neutron monitoring stations. The results indicated that the decrease time of the FD event is positively correlated with both the altitude and the geomagnetic cutoff rigidity of the neutron monitor stations. The recovery time shows a positive correlation with altitude, geographic longitude, and the absolute value of geographic latitude. The amplitude of the decrease is strongly positively correlated with the absolute value of geographic latitude, but strongly negatively correlated with geomagnetic cutoff rigidity. The end time of the decrease exhibits a strong positive correlation with both altitude and geomagnetic cutoff rigidity.