Jerks abound: An analysis of geomagnetic observatory data from 1957 to 2008

AbstractWe present a two-step method for the removal of external field signals and the identification of geomagnetic jerks in magnetic observatory monthly mean data, providing quantitative uncertainty estimates on jerk occurrence times and amplitudes with minimal a priori information. We apply the method to the complete time series of X-, Y- and Z-components at up to 103 observatory locations in the period of 1957–2008. We find features fitting the definition of jerks in individual components to be frequent and not globally contemporaneous. Identified regional jerks have no consistent occurrence pattern and the most widespread in any given year is identified at