Signs of a new geomagnetic jerk between 2019 and 2020 from Swarm and observatory data

Following the observed pattern of a new geomagnetic jerk every 3-4 years, certain predictions suggested that a new event should occur around 2020 after the one observed around 2017.5. In this work, we explore this scenario by analysing the secular variation of the East geomagnetic field component in both ground and satellite geomagnetic data. At ground, we use the available data from 2015 to 2021 in 10 observatories worldwide distributed. This analysis shows the occurrence of the mentioned jerk in mid-2017 at observatories located in the Pacific region, but also reveals a new jerk between mid-2019 and early 2020 with a clear global character. Swarm satellite data also corroborate these findings by means of the secular variation estimated using virtual observatories at 440 km altitude. In addition, a general view using the most recent CHAOS geomagnetic model confirms the global character of the 2020-jerk with V-shaped secular variation changes in meridional sectors covering the Eastern Pacific, America, Asia and the Indian Ocean; and Lambda-shapes in Europe, Africa and Western Pacific. The radial geomagnetic field at the core-mantle boundary is investigated as the origin of the new jerk. Results show that the global-average secular acceleration of the radial field exhibits a new pulse at mid-2018, establishing the starting epoch of the 2020-jerk. Highlights - Observatory and Swarm data reveal a new geomagnetic jerk around 2019-2020. - A very recent geomagnetic field model indicates the global character of the new jerk. - A new pulse at the CMB around mid-2018 seems to be the starting point of this jerk.

Automated summary

Research indicates that a new geomagnetic jerk occurred around 2019-2020, with global characteristics observed in both ground and satellite magnetic data. The most recent geomagnetic field model confirms the worldwide nature of this new jerk, while a new pulse at the core-mantle boundary appears to mark the onset of this event.