Attaining a quantitative understanding of relativistic electron variability in the radiation belts is a major focus of current radiation belt research. Quantifying and understanding electron losses in now recognized as an integral part of understanding this variability. A major question is how to quantify the relative importance of acceleration processes versus the loss processes. Balloon-based experiments directly measure precipitation and thus provide a method for quantifying and studying losses. This project will use two small balloons, each carrying an X-ray spectrometer for measuring relativistic electron precipitation (REP) and a photometer tuned to detect proton precipitation. The balloons will be launched from Ft. Churchill, Manitoba during winter 2004/2005. The proposed campaign will support and take advantage of an already existing balloon campaign funded by the NSF Antarctic Aeronomy and Astrophysics Program entitled, "Balloon Observations of MeV Electron Precipitation", lead by U. C. Berkeley, in which four small balloon payloads carrying X-ray instrumentation will be launched from the South African Antarctic station, SANAE. This project will obtain the first conjugate balloon observations of REP sensitive to MeV energies. Since the northern hemisphere observations being made by this project will take place during the northern winter, it allows the use of sensitive optical measurements of proton precipitation, which cannot be done in the sunlit Antarctic. The project will involve several undergraduates in the research and thus promotes educational goals as well as directly contributing to our knowledge of the radiation belts.
