Correlation of High‐Latitude Scintillation With Auroral Precipitation: Case Studies Using GNSS Radio Occultation Data From PlanetiQ

Abstract

This study presents a survey of high‐latitude ionospheric scintillation using GNSS radio occultation (RO) data from the PlanetiQ satellite. The analysis examines 483 high‐latitude RO tracks between January and May 2023, with 371 tracks exhibiting scintillation events. Under our classification scheme and threshold criteria, our results show that amplitude scintillation events occur more frequently than phase scintillation events, contrasting with ground‐based observations that predominantly report phase scintillation at high latitudes. Beyond possible dependence on event‐identification criteria and thresholds, this difference is attributed to the RO raypath geometry, which allows extended horizontal interaction with ionospheric irregularities where diffraction effects may cause amplitude scintillation. Additionally, the longer propagation path through ionospheric irregularity region may enhance diffraction effects, though RO geometry interpretation requires validation through modeling. Both amplitude and phase scintillation were prevalent during geomagnetically quiet and disturbed conditions, with median Kp values ranging from 3 to 3+. Near conjunctions of DMSP Special Sensor Ultraviolet Spectrographic Imager and Special Sensor J observations with scintillation events indicate correlation between scintillation and regions of enhanced low‐energy electron precipitation (∼100–500 eV) along the RO raypaths during quiet, active and storm conditions. Small‐scale (≈20 km) electron density gradients from DMSP Ion Velocity Meter measurements also occurred during these conjunction events. These findings demonstrate temporal and spatial associations between scintillation events and low‐energy electron precipitation/enhanced density gradients, consistent with (though not definitively proving) precipitation‐induced ionospheric irregularity formations as a mechanism for F‐region high‐latitude scintillation. These results demonstrate GNSS RO as a powerful tool for monitoring high‐latitude scintillation and its connection to auroral processes.