The impact of Mother’s Day Storms in May 2024 on Precise Point Positioning at mid-latitudes

Geomagnetic storms generate disturbances in the ionosphere that can significantly affect the quality of Global Navigation Satellite System (GNSS) signals transmitted through the ionosphere. While many studies have investigated their impact on GNSS at low or high latitudes as they are the regions mostly affected by ionospheric disturbances, this study focuses on the mid-latitude area affected by a recent superstorm event in May 2024, namely Mother’s Day storm. Due to the severity of the Mother’s Day storm, the visible blueprint of the ionospheric irregularities – aurorae and stable auroral arcs – were observed at mid-latitudes worldwide, thus motivating our research. By probing the GNSS measurements recorded at a GNSS receiver, the ionospheric variations and their impact on the GNSS positioning can be evaluated. We processed GNSS data recorded at Lampedusa Island in Italy during the Mother’s Day storm and analyzed the variation of the total electron content (TEC), scintillation indices, and the accuracy of precise point positioning (PPP) results. During the storm, the TEC dramatically decreased, which suggests no significant impact on positioning since TEC is positively correlated with the ionospheric code delay and phase advance in the GNSS signals. However, the PPP results indicate that the geomagnetic storm degraded the GNSS positioning considerably due to the scintillation occurrence during the storm event.