Otto Kärhä

and 2 more

Space weather is a significant threat to modern society. Charged particles, Ground Induced Currents (GICs), and changes in the magnetosphere and atmosphere threaten a wide range of critical infrastructure on the Earth’s surface and in space. Possible damages may be direct or indirect results of these natural hazards. Spatial variations in magnetic disturbances during geomagnetic superstorms are not well understood because such storms are rare. However, a growing number of studies focus on these variations. Here, we show that the strongest disturbances in the magnetic north (X) component during the 2024 Mother’s Day storm occurred at Nurmijärvi (NUR) station, which is located at latitude 57° in Corrected Geomagnetic (CGM) coordinates. During the 2003 Halloween storm, the largest disturbances of this component occurred at Oulujärvi (OUJ) station, which is located at latitude 61° (CGM). Superstorms can have a stronger effect on the strength of the magnetic field in the sub-auroral regions, making the lower latitudes prone to large regional variations during the most powerful events. However, during the Mother’s Day storm, the most significant time derivatives (dH/dt) of the magnetic field, widely used as a proxy for GICs, occurred at higher latitudes than during the Halloween storm. The spatial distribution of different types of magnetic disturbances highlights the variability of the magnetic weather coupled with the ground conductivity structure and latitudinal influence.