A Statistical UltraLow Frequency (ULF) Fingerprint of Magnetic Storms and Its Application to Electron Energization

Loyola Marymount University, Los Angeles CA

Investigators

Abstract

A number of previous investigations have established a close relationship between the solar wind and Ultra-Low Frequency (ULF) waves in the magnetosphere. An area of much recent interest is the rapid enhancement in the number of relativistic electrons in the inner magnetosphere during magnetic storms. While research results have suggested a strong correlation between ULF wave power and high fluxes of these energetic electrons, new fundamental and important questions have been raised. These questions include: (i) how does one differentiate between magnetic storms with relativistic electrons and magnetic storms without relativistic electrons? (ii) what is the relative importance of broadband versus narrowband waves in the energization of relativistic electrons? and (iii) what are the duration and timing of ULF power necessary to produce relativistic electrons? The primary objective of this project is the development of a statistical "fingerprint" of magnetic storms based on a time profile of ULF wave power. Components of this fingerprint will include profiles of the development of Pc3 - 5 powers as well as power indices. This will be done for both intense and moderate magnetic storms as defined using the Dst index. By comparing this fingerprint to the temporal variation of relativistic electron flux, this project will be able to address questions on electron energization such as the ones listed above. The study will be based on over 4 years of geosynchronous satellite observations. During this period, geosynchronous measurements of high-energy electron flux are readily available, and a preliminary survey has revealed the presence of nearly 20 major storms (Dst ~100 nT) and a far greater number of moderate storms, thus allowing for the compilation of a large database well-suited for a statistical study. This project will also include: (1) the integration of research and education, the participation of underrepresented groups, and enhanced research and education infrastructure. Specifically, undergraduates at Loyola Marymount University will be provided the opportunity to participate actively in research, thus enriching their educational experience and providing them with greater preparation for their professional careers. The diversity of the student population at Loyola Marymount will be reflected in the research team. This research will be performed with collaborators at large research institutions, resulting in a partnership that will reinforce the excitement of space physics research among the student scientists.