This proposal seeks funding to resume operation of the VLF Beacon Transmitter at the South Pole Station used to quantify temporal and spatial variations in the state of the lower ionosphere between the polar cap and subauroral zone, to determine the ionosphere's response to precipitation of highly energetic radiation belt electrons and solar protons, and to monitor the loss of these particles into the atmosphere. Although fluctuations in the relativistic particle population are extensively observed on satellites, little is known about the extent of associated precipitation into the ionosphere. Upon precipitation, these highly energetic particles penetrate to altitudes as low as 30-40 km, producing ionization, X-rays, and possibly affecting chemical reactions involving ozone production. It is proposed to continue recording the VLF beacon's signal at various Antarctic coastal stations (Palmer, Halley, etc). The broader impact of the proposed program includes the synergistic use of the South Pole VLF beacon with ongoing satellite-based measurements of trapped and precipitating high-energy electrons both at low and high altitudes and with other Antarctic Upper Atmospheric research efforts, such as the Automatic Geophysical Observatory programs and routine upper atmospheric observations at manned bases. The proposed project also promotes international collaboration via multi-points recording of the South Pole VLF beacon signal while providing the basis of a graduate or doctoral student thesis.
