Influence of ionospheric disturbances on GNSS scintillations at auroral latitudes

Abstract

The impact of geomagnetic disturbances during two different types of magnetic storms (CME and CIR storms) on GNSS (GPS, GLONASS) signal scintillations was compared using data from the Septentrio PolaRx5 receiver in the city of Apatity (Murmansk region, Russia). The events of November 3-4, 2021 and October 11- 12, 2021 are considered. The analysis shows that the significant growth of phase scintillations occurs not only during nighttime and evening substorms as usually, but also during daytime geomagnetic disturbances, accompanied by the positive magnetic bay. No increase in amplitude scintillations was found during the considered events for the GPS and GLONASS satellites. It is shown that the increase in the phase index of scintillations is not always proportional to the intensity of the geomagnetic disturbance. Sometimes smaller geomagnetic disturbances can lead to the higher phase scintillations. It is found that the level of phase scintillations correlate with the growth of the amplitude of ULF waves (Pi3/Pi2). The strongest phase scintillations coincide with the appearance of the east-west oriented aurora arc, registered by all-sky camera at Lovozero station, and ULF waves. This fact confirms the idea about the role of ULF waves in producing the auroral arc.