ELF/VLF Studies of Whistler-mode Waves, Lightning Discharges, and Gamma-ray Events from Palmer, Antarctica

Stanford University, Stanford CA

Investigators

Abstract

This award is to address outstanding scientific questions in the areas of magnetospherically generated whistler-mode waves, thunderstorm activities and global lightning discharges associated with terrestrial gamma-ray flashes, and their ionospheric effects by investigating experimental data collected by the ELF/VLF radio receiver deployed at Palmer Station, Antarctica. During and in the aftermath of geomagnetic storms wave-particle interactions result in large variations of the energetic electron population that form the Earth's radiation belts. Magnetospherically generated emissions from those wave-particle interactions are regularly observed at Palmer Station and can be used to determine magnetospheric source regions of these waves and their influence on the radiation belts dynamics. Palmer data will also be used to explore the outstanding question of the source of plasmaspheric hiss emissions, which may be terrestrial lightning or magnetospheric chorus. In addition, several scientific and industrial enterprises rely on the real-time detection and geolocation of lightning strikes from Palmer. Continued wave observation at Palmer will allow for the expansion and refinement of the current geolocation algorithm. Terrestrial gamma-ray flashes (TGF) have been strongly associated with lightning discharges, but the exact mechanism involved in their generation remains unknown. The high signal-to-noise ratio of sferics recorded at Palmer can be used to determine the properties of TGF-associated lightning, including which particular types of lightning may cause TGFs, and their geographical source. In terms of broader impacts, the research program will advance discovery and understanding while promoting teaching, training, and learning through the participation of graduate and undergraduate students in the project. The program will enhance infrastructure for research and education through collaborations and partnerships with national and international institutions.