A Statistical Survey of Lifted F2 Layer Peaks in the Polar Cap Ionosphere Observed by RISR-N

In this study, we conducted a statistical survey of long-pulse incoherent scatter radar observations of the F-region Ionosphere by the Resolute Bay Incoherent Scatter North (RISR-N) station. The observations were collected between 2009 and 2024, roughly spanning the entire solar cycle 24. The altitude (hmF2) and electron density (NmF2) of the F2 layer peak were identified through a non-linear least squares fitting of the electron density vertical profile to an Epstein Layer Model. Once fit, each time step’s fitted hmF2 and NmF2 were compared to empirical model outputs from the International Reference Ionosphere (IRI) Model and the Empirical Canadian High Arctic Ionosphere Model (E-CHAIM) to determine whether the RISR-N observations were lifted or dense relative to the empirical model estimates. These lifted and dense events were then scrutinized for their background solar wind and geomagnetic conditions from NASA’s OMNI Satellite. We observed that lifted events and dense events are distinct in their distribution, leading to few events in the database being both lifted and dense. Lifted events were observed occurring during times of fast solar wind, whereas dense events occurred during times of slow solar wind relative to the underlying distribution of solar wind speed from OMNI between 2009 and 2024. Also, the largest geomagnetic storms of solar cycle 24 and the beginning of solar cycle 25 do not produce lifted events observed by RISR-N. The events with the highest electron density and lifted hmF2 originate from the storms of moderately negative Dst.