GPS scintillation enhancements associated with aurora and cosmic radio noise absorption

Abstract

Unpublished article: The coincidence of ionospheric scintillation at L-band frequencies with auroral arcs and increased riometric absorption was observed from 01:00 UT on 28 April 2007 by co-located instruments at 72ºS in Antarctica during the recovery phase of a substorm. At about 01:31 UT a stable omega-like arc structure formed with pulsating patches equator ward and dark regions east of the pole ward direction. This structure moved fast eastward, slowed down and broke up in pulsating patches. Enhanced ionization associated with this structure and other auroral arcs, as recorded by an all-sky video camera and an 64 beam imaging riometer, was observed to coincide with phase scintillation along ray paths of GPS satellites. Connection between enhanced ionization in the D-region, as implied by enhanced imaging riometric absorption observed in this study, and phase scintillation at GPS frequencies, may be indicative of the height distribution of ionization structures giving rise to scintillations.