Recently, small scale azimuthal structuring in optical signatures associated with low frequency PC1/2 wave activity has been observed around the time of substorm onset. While the characteristic…

This is a NASA grant awarded to Andrews University, a private university and non-profit educational institution located in Berrien Springs, Michigan. The $142,200 grant is for a research project that aims to provide a better understanding of the ballooning instability in the near-Earth plasma sheet by comparing THEMIS, DMSP, and ground-based observations of low-frequency waves with azimuthal structuring of electron precipitation against state-of-the-art 3D global electromagnetic gyrokinetic simulations. The research addresses key science questions related to the stability of the ballooning mode, its observational signatures, and how those signatures compare with in situ and remotely observed wave signatures. This project advances NASA's science goals to understand the connection between the solar wind and magnetospheric dynamics, as well as the agency's strategic goal to develop the capability to predict extreme and dynamic conditions in the space environment. The grant does not have a set-aside designation, indicating it was awarded through full and open competition.

Recently, small scale azimuthal structuring in optical signatures associated with low frequency PC1/2 wave activity has been observed around the time of substorm onset. While the characteristic frequency and kinetic-scale structuring have been attributed to the onset of a kinetic ballooning instability, there has been no rigorous comparison between the observations and theoretical MOD- ELS. The aim of this proposal is to provide better understanding of ballooning instability in the near-earth plasma sheet by comparing themis, dmsp, and ground based observations of low frequency waves with azimuthal structuring of electron precipitation with state-of-the-art 3D global electromagnetic gyrokinetic simulations of the ballooning instability in a realistic stretched dipole geometry. In particular, we will address the following science questions: how does the stability of the ballooning mode depend on the growth phase development of plasma and magnetic ELD profiles?; what are the observational signatures of the instability?; and how do those signatures compare with in situ and remotely observed wave signatures? Because these waves are observed to precede substorm onset, this study should also provide insight about the conditions favorable to initiation of substorms. The project advances the 2010 NASA SMD science plan goal to understand the connection between the solar wind and magnetospheric dynamics involving processes at work over large and small scales because IT describes how small-scale physics on kinetic scales can a ECT global stability of the magnetosphere. This proposal also addresses science goals and objectives that have been given priority in appendix 1 of the 2010 heliophysics science plan. The gyrokinetic simulations will provide better understanding of the conditions in the magnetotail that are favorable for substorms. These advances will address the NASA strategic goal to understand fundamental physical processes of the space environment and more specically to develop the capability to predict extreme and dynamic conditions because there should be better understanding of where/when substorms occur and we will provide predictions about observational signatures.