Great Lakes Region Morphology and Impacts of March 17, 2015 SED Geomagnetic Storm

Under quiet geomagnetic conditions, the mid-latitude ionosphere is relatively uniform with little spatial variation in electron density. However, during intense geomagnetic storms, density gradients associated with Storm Enhanced Density (SED) plumes and Sub-auroral Polarization Streams (SAPS) can move across the dayside mid-latitude ionosphere producing small spatial scale density structure that may be connected to ionospheric scintillation. The evolution of the SED plume during the March 17, 2015 "St. Patrick's Day Storm" is investigated using aggregated data from high resolution GPS receivers at the University of Michigan and throughout the Great Lakes region. Structural density features in the SED gradient can be observed and compared to GPS scintillation measurements—providing insight into the physical mechanisms behind ionospheric scintillation.