Fig. 4From: Ground geomagnetic field and GIC response to March 17, 2015, stormGlobal \(\varPhi\)-LT maps for the time moment 1748 UT (substorm #4) of the ΔX variations (upper panel) and magnetic variability |dB/dt| (bottom panel). Small black crosses denote the station location. No OVATION model data are available for this periodBack to article page