Observed high-latitude GNSS disturbances during a less-than-minor geomagnetic storm

This paper presents the effects of a weak geomagnetic storm event on 17 January 2013. While the Kp index reached a maximum of only 4, this event still caused severe disturbances for Global Navigation Satellite Systems (GNSS)-based positioning services at high latitudes. We present data from the Norwegian Mapping Authority's Real Time Ionospheric Monitor, based on a dense network of geodetic receivers and scintillation indices from scintillation receivers located in Norway. In northern parts of Norway, the centimeter positioning service was severely disturbed for hours. Service-monitoring measurements showed that the effect was significantly worse for a receiver far away from the nearest network reference station.