High-latitude day-time Pc1–2 continuous magnetic pulsations: A ground signature of the polar cusp and cleft projection

Abstract

New observational and dynamical morphological results of high-latitude Pc1–2 (0.2–10 s) magnetic pulsations observed at Davis (inv. 74.5° S), Antarctica during solar maximum are presented. An interesting regime of Pc1–2 containing structured, semi-structured and unstructured, long duration ( τ ~ 1–10 h) magnetic pulsation bands ( T ~ 2–10 s), which appear to maximize in occurrence frequency and amplitude under the projection of the dayside polar cusp/cleft is examined. An account of these emissions is given, including periods, amplitudes, duration, diurnal and seasonal distributions, polarization, power spectra and their association with magnetic activity ( K p ). Moreover, a review of the literature reveals the necessity for a universal convention to clear up the apparent paradox and confused nomenclature existing in the literature on high-latitude Pc1–2 magnetic pulsations. This study concludes that Pc1–2 magnetic pulsations as reported provide a ground diagnostic estimate as to whether a station lies under the projection of the polar cusp/cleft.