Spatial distribution of total electron content in the arctic region of Russia from GPS data

Preliminary results of studying the spatial distribution of the total electron content (TEC) in the Arctic region of Russia are presented. The study is based on double frequency phase data obtained at four high-latitude GPS stations (LOVJ, Murmansk; NRIL, Norilsk; TIXI, Tiksi; BILB, Bilibino) on May 4-6, 2013 at 04:00-10:00 UT. On some receiver - GPS satellite rays northward of the stations, we have detected sharp TEC decreases or increases which argue for existence of a low electron density region (ionization trough) in the ionosphere. As found from the analysis of displacement of receiver- satellite rays, the ionization trough was located at latitudes of 72-84° N and longitudes of 0-200° E. The obtained results are consistent with numerical simulation data.