Map indicating the position of the GNSS receivers and ionosondes considered along this work. In the main plot: purple downward-pointing triangles labeled with uppercase letters are the DGSs listed in Table 1, red dots accompanied by lowercase letters correspond to the GNSS receivers listed in Table 2, and the blue dashed line corresponds to the magnetic equator. The inset is a zoomed-map of the red diamond symbol in the Caribbean region and illustrates the dense Caribbean network used to perform the velocity analysis of EPBs. Maps have been generated by means of the GeoPandas library in Python (Jordahl et al., 2020).