Daytime measurements of optical auroral emissions from Antarctica

Abstract

Optical methods have enabled us to detect auroral emissions during daytime conditions, and to identify a narrow latitudinal region of energetic particle precipitation from the Indian station Maitri (11° 38'E; 70°45'S; 62.8°S I-lat.) in Antarctica. These observations are new. The energetic particles originate within the closed geomagnetic field lines close to the plasmapause region and maximize ~0830 h MLT (Magnetic Local Time) (~1200 UT). Enhanced proton precipitation activity could also be inferred during a moderate geomagnetic storm, suggesting the enhancement/activation of acceleration mechanisms during this event.