Isolation of ionospheric events in GNSS phase scintillation observations in the Arctic

In the Arctic, space weather poses a threat to satellite-based navigation by inducing fluctuations in the phase of the radio signal, termed phase scintillation. Therefore, reliable space weather alerts and scintillation models are needed for better warnings and understanding of the impact. For real-time space weather alerts to be valuable, identifying and removing high scintillation values caused by other processes is crucial before issuing space weather alerts. Similarly, for a database of a scintillation model, a distinction between the origin of extreme phase scintillation values could increase the model's integrity. This can be a challenge for the phase scintillation index, σ_ϕ, where other events, such as radio-interference, can result in high phase scintillation values that are not space weather related. In this paper, two methods for evaluating the origin of high σ_ϕ values are examined and their use in combination is discussed. The findings show that for three of the station sites in Greenland, less than one percent of high σ_ϕ values were not space-weather related. For the data collected in Kulusuk 46.85 percent of high σ_ϕ were not space weather and 53.15 % were related to space weather. Therefore, isolating these allows for a significant reduction of misassigned σ_ϕ, which can improve both GNSS-based modelling and alert systems.