The overarching goal of this award is to study responses of the sub-auroral ionosphere to the active geomagnetic periods via investigations of the ground-based observations of stable auroral red (SAR) arcs from two geomagnetically conjugate locations: the Millstone Hill Observatory in Massachusetts and British station Rothera located at the Antarctic Peninsula. Additional data from the South American Magnetometer B-field array (SAMBA, extended from Chile to the Antarctic Peninsula) and the Millstone Hill Incoherent Scatter Radar and other geophysical instruments will be utilized to understand the SAR arcs' conjugate behavior and answer some outstanding questions of space physics: (a) what is the symmetry (or lack of) for the sub-auroral ionosphere responses in both the Northern and Southern hemispheres to the magnetospheric forcing; (b) how longitudinal variations in the SAR arc brightness correlated with the Earth's ring current properties; (c) how to interpret dynamic structures inside the arcs and finger-like features connecting them to the diffuse aurora; (d) how the modeling of SAR arc features at both hemispheres can help addressing seasonal changes in the ionospheric responses, and (e) what nighttime thermospheric gravity waves (GWs) and medium scale traveling ionospheric disturbances have in common, thus advancing the understanding of magnetosphere-ionosphere coupling. The Defense Meteorological Satellites Program (DMSP) and the NASA's Radiation Belt Storm Probes (RBSP) will provide key information of ionospheric parameters and energetic ions in the ring current for this study. The project involves international collaboration and trains a graduate student.
