Fig. 5
From: Signs of a new geomagnetic jerk between 2019 and 2020 from Swarm and observatory data
Maps of the secular acceleration (SA) of the radial field Br at the CMB and the spatial average of its square value given by the black curve. Maps in a February-2016 and b September-2018 correspond to the two maxima observed in the black curve (yellow squares). Map in c June-2017 corresponds to the minimum presented in the black curve (green square) and map in d June-2020 is plotted at the end of the time window (red square) where the black curve is decreasing