GPS Loss of Lock Events and Their Dependence on the Interplanetary Magnetic Field Orientation

The study investigates the influence of interplanetary magnetic field (IMF) orientation on loss of lock (LoL) events in Global Positioning System signals. We analyzed LoLs recorded on two Swarm satellites between July 2014 and December 2021, examining how the signs of the IMF Bx, By, and Bz components affect the distribution of events at high latitudes. Our results reveal an asymmetric distribution of LoL events over 75° magnetic latitude. In the Northern hemisphere, more events occur in the post‐noon sector with negative IMF By, and in the pre‐noon sector with positive IMF By. Conversely, in the Southern hemisphere, pre‐noon events increase with negative IMF By, while post‐noon events increase with positive IMF By. At lower latitudes (50°–75°), IMF By does not significantly affect the event distribution, which mainly concentrates in the night sector for both hemispheres. Additionally, we found a connection between IMF By and Bx, primarily due to the IMF spiral structure. Finally, we discuss our findings in the context of the SuperDARN data‐driven model of ionospheric convection patterns, which shows that LoL events frequently cluster in the cusp region, as well as the area where the two convection cells separate. Key Points The number of Global Positioning System (GPS) loss of lock (LoL) events is affected by the interplanetary magnetic field (IMF) orientation GPS LoLs are most common at the cusp, the area of separation between two convection cells, and the nightside of the auroral oval The duration of GPS LoL events does not appear to be affected by the strength of the IMF