Detection of the 2020 Geomagnetic Jerk Using near Real-Time Data from the "St. Petersburg" and "Klimovskaya" Magnetic Observatories

Highly accurate observations of the Earth's total magnetic field vector promptly derived from the data recorded at the "St. Petersburg" (Leningrad oblast) and "Klimovskaya" (Arkhangelsk oblast) magnetic observatories are studied. It is shown that such data can be used for detecting geomagnetic jerks in secular variation records with a minimum time delay, which is difficult using the most recent models of the Earth's core magnetic field. Based on the data over 2015-2022, we identify two jerks of 2017 and 2020, which fit well into the three-year quasi-periodicity observed since the beginning of the study of the rapid variations of the core field. The result confirms the hypothesis of the wave nature of the underlying processes in the liquid core.