Observation and Modeling of Global Propagation of Pi2 Waves

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Storms in the space plasma environment surrounding the Earth create ultra-low frequency (ULF) radio waves. These waves transport energy throughout the magnetosphere into lower levels of the atmosphere. Understanding these waves is important to national security and commercial interests, since they contribute to space weather effects to our satellites and space-based communications. Additionally, a physics graduate student will be trained in research techniques engaging with researchers from multiple scientific institutions. The investigation seeks a quantitative understanding of processes associated with global propagation of a type of ULF waves known as Pi2 waves. The waves are excited in the nightside magnetosphere at the beginning of magnetospheric substorms and propagate to the dayside and to the ground. How the waves maintain their energy as they propagate over long distances within the structured magnetosphere and through the ionosphere is not well understood. They will tackle this problem by analysis of data from spacecraft and ground and by conducting numerical simulation incorporating realistic magnetosphere and ionosphere. They will use data from the Radiation Belt Storm Probes and Arase spacecraft, which have been in concurrent operation for more than 1.5 years, to cover different magnetic local times and magnetic latitudes. In the simulation, we will use a dipole field linear MHD code that incorporates realistic ionospheric boundary conditions and is capable of producing ground-level wave fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.