An investigation of the correlation between ionospheric and geomagnetic variations using data from the GPS and INTERMAGNET networks

Comparative analysis of total electron content (TEC) variations and geomagnetic field variations during the major magnetic storm on 29–31 October 2003 (Kp 4–9) was carried out for the middle-latitude ionosphere. We analyzed data of GPS receivers and magnetic observatories, located in the north-east, north-west and south-west parts of North America and in central Europe. It was found that magnetic field intensity variations for the period range of 30–60 min (corresponding to the acoustic-gravity waves, AGWs) correlate well with TEC variations of the same time scale. For moderate geomagnetic activity period on October 13–18, 1999 (Kp 2–4) a similar dependence was not noticed, according to analysis of data from GPS receivers located in south-west USA, California. However, correlation between TEC variation intensity in the period range of 30–60 min and slow magnetic field changes was observed. Thus, connection between TEC variations within the period range of the AGWs and magnetic field variations is perceptible.