Examine Periodic Variation
Pc3 and related geomagnetic pulsations are observed as periodic changes on time scales of tens of seconds. Each analysis states the period range used, sampling interval, analysis window, and frequency resolution, and examines both waveforms and spectra. An increase in amplitude alone does not identify its cause.
Compare Stations
Comparisons between stations examine timing, phase, magnetic components, and data gaps. Station latitude and local noise help distinguish a widespread feature from one confined to a single location.
Solar-wind conditions, the state of the magnetosphere, and daily variation provide additional context.
Check the Effects of Filtering
Band extraction can change waveforms and the appearance of features near the ends of a record. We check detrending, filters, gap interpolation, and edge handling by comparing processed and unprocessed data. Important features are also examined under alternative settings.
Read Results as Research Evidence
Timing agreement between stations or datasets can support investigation of a relationship. It does not by itself prove a common cause or propagation path. This analysis is not intended to predict earthquakes, eruptions, or space weather, or to issue warnings.
See the method pages for processing conditions and guidance on reading figures.