Pc5 Pulsations in the South Atlantic Magnetic Anomaly

This paper investigates the Pc5 magnetic pulsation characteristics influenced by the South Atlantic Magnetic Anomaly (SAMA) in a moderate geomagnetic storm through records analysis of geomagnetically conjugate stations interlinking both hemispheres. This study uses the horizontal magnetic components measured in the same time interval in two typical longitudes: the America-SAMA region and Asia-Pacific one, whose stations are under equivalent McIlwain L-parameter (L-shell). Our procedure uses those data recorded simultaneously in six conjugate-station pairs to identify and characterize the Pc5 pulsation. The methodology integrates spectral analyses based on fast Fourier transform and wavelet transform techniques, obtaining signal characterizations and coherence analysis to highlight the Pc5 pulsation dynamics. As a result, work found that Pc5 pulsations showed simultaneous and similar patterns in the occurrence intervals in the Asia-Pacific region, reinforcing previous results from more restricted research. Concerning the America-SAMA region, the Pc5 pulsation amplitudes in the Northern hemisphere stations presented pulsation amplitudes following the Asia-Pacific amplitude behavior. The pulsation amplitudes were higher in the SAMA region than those in the Northern hemisphere. Also, in the SAMA, concerning the conjugate stations, Pc5 pulsation presents the highest energy values in the typical Pc5 spectra during storm intervals with higher intensity. Between the conjugate pairs, pulsations showed moderate to low signal coherences and phase lags.