Monitoring of GNSS Scintillation Indices during the MOSAiC Expedition: Preliminary Results of Ship-borne and Station-based Observations in the Arctic

Abstract

Polar regions are of particular interest to study the interaction of space weather (solar radiation and particle precipitation) with the Earth’s atmosphere and magnetosphere. We focus here on space-weather induced irregularities of electron density in the upper atmosphere and their impact on radio signals. Such irregularities can disturb radio communication (particularly in air traffic) and radio navigation with GNSS (Global Navigation Satellite Systems) in the polar regions. The global network of GNSS stations to monitor the space weather impact is sparse at high latitudes. The permanent stations, located below 80°N, cannot reach a complete monitoring coverage in the Arctic. The MOSAiC expedition provided an excellent opportunity to collect GNSS data beyond 80°N over a long period of about seven months (Oct 2019 to Apr 2020). We focus, here, on the GNSS setup that was drifting with the research vessel Polarstern in the Central Arctic. Additionally, data of a GNSS scintillation station at Ny-Alesund, Svalbard (79°N) is analyzed. In general, this period (close to solar minimum) had rather calm space weather conditions and the indices S4 and σφ did not reach the thresholds of severe amplitude or phase scintillation. However, anomalies of σφ on a weak to moderate scale occur persistently for the central Artic ship setup and the Ny-Alesund station. Their comparison reveals differences in temporal distribution that are further investigated. Still, the origin of particle precipitation in the polar cap or cusp region has to be clarified. Based on the preliminary results, we found that a ship-borne GNSS setup (under moderate sea state conditions) can contribute to the detection of spaceweather induced ionospheric irregularities and we conclude that monitoring over the oceans (especially in the central Arctic) can benefit from further observations of this kind.