| Summary: | The occurrence of Pcl-2 ULF waves in Scott Base and Casey Antarctic magnetometer data has been examined with the objective of determining whether the source region for these waves is located in the Earth's cusp/boundary layer region or the magnetosheath. In particular we explore the hypothesis that some Pcl-2 events are propagated along open field lines which convect over the southern polar cap. For a selected event the location of Scott Base with respect to the open/closed field line boundary was independently determined using DMSP spacecraft particle data and well established particle energy and flux criteria. This event provides evidence that Pcl-2 waves can be seen on the ground well inside the polar cap. The possibility of propagation in the ionospheric waveguide, away from the footpoint of the source, is investigated using numerical modelling and realistic ionospheric parameters. Under the modelled conditions we find a modification of wave ellipticity which excludes this explanation for the polar cap Pcl-2 seen in the event study.
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