Characterizing the dayside auroral ionosphere with ISR elevation scans and field-aligned observations

The dayside auroral ionosphere exhibits significant variability because of its strong coupling to the magnetosphere-solar wind system. Dayside aurora is typically driven by soft precipitation, which also produces enhanced electron temperatures at high altitudes and can be easily measured by Incoherent Scatter Radars. Using EISCAT Svalbard radar (ESR) fast elevation scans, we identify the equatorward boundary of the dayside aurora and extract near-simultaneous ionospheric altitude profiles within and outside the auroral region, allowing for an investigation of ionospheric behavior with respect to the relative distance from this boundary. In addition, the large data set of ESR field-aligned observations facilitates statistical analysis over two solar cycles. Together, both field-aligned observations and elevation scans contribute to a characterization of the dayside auroral ionosphere.