(a) Mean value of R_vc over longitude at latitudes 45° N, 0° N, and 45° S; (b) impact area of energetic particles at R_vc equal to 2.5 GV, 5 GV, and 7.5 GV; (c) impact area of energetic particles at R_vc equal to 2.5 GV and 5 GV, with solid lines (dashed lines) indicating the impact area in the northern hemisphere (southern hemisphere), respectively; (d) global cosmic ray proton flux accessing the Earth’s atmosphere; (e) cosmic ray proton flux reaching the Earth’s atmosphere due to its rigidities during the last 100 ka. For comparison, today’s values calculated using the International Geomagnetic Reference Field (IGRF) at epoch 2020 (Alken et al., 2021) are included in panels a and b as dashed lines.