Fig. 4
From: Signs of a new geomagnetic jerk between 2019 and 2020 from Swarm and observatory data
Maps of the Y secular acceleration changes (δSA) on a July 1st 2017 (2017-jerk) and b May 1st 2019 (2020-jerk) at the Earth’s surface obtained from the CHAOS-7.7 model. White stars in both maps indicate the location of the selected observatories. The estimated amplitude of δSA from observatory data (Table 1) is also given in parentheses (values in nT/year2). Amplitudes are not estimated when the jerk was not evident at that observatory or not enough data are available