Fig. 1

Location of geomagnetic observatories used in this study (green dots). Black lines depict \(\pm 55^\circ\) quasi-dipole latitudes. Relevant information about these observatories is summarized in Table 1
Location of geomagnetic observatories used in this study (green dots). Black lines depict \(\pm 55^\circ\) quasi-dipole latitudes. Relevant information about these observatories is summarized in Table 1