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

Abstract

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 Λ-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.

Natural potentials concurrent to geomagnetic variations in the cryolithozone

“…Results allow the detection of a new jerk between the end of 2019 and beginning of 2020. In contrast with the regional character of the previous one in 2017, the 2020-jerk is seen more globally according to the observations and CHAOS model estimations [4].…”

Detection of a New Large Free Core Nutation Phase Jump

“…More detailed investigations of this effect were conducted by [18,19,[24][25][26]. Recently, [27] reported about newly detected signs of a start of a GMJ in 2020, which is likely connected with the FCN phase jump 2021-2022 detected in this work. Based on previous studies, this assumption looks highly reasonable.…”

Rescue and quality control of historical geomagnetic measurement at Sheshan observatory, China

“…In addition, there were two local events which occurred in 1949 (Mandea et al, 2000) and 2011 (Chulliat and Maus, 2014;Kotzé and Korte, 2016). In 2017, there were similar characteristics of geomagnetic jerks, which may be a new geomagnetic jerk (He et al, 2019;Pavón-Carrasco et al, 2021). The jerks are more easily seen in the eastward component (Y ) of the geomagnetic secular variation.…”