Variability of the Sq Focus Position in the South American Continent

摘要

The daily variation of the H component at Pilar (31.7 S, 63.9 W) and Trelew (43.3S, 65.3 W) in the South American continent indicates a great variability in amplitude from season to season and even from day to day. However, Pilar always remains equatorward of the southern Sq focus. On the other hand, Trelew is in most cases slightly poleward of th Sq focus; but the focus has large latitudinal excursions above and near Trelew. A cause of this variability could be the encroachment of polar ionospheric current systems into the low latitude ionospheric Sq current system.