Position of the main ionospheric trough polar wall in magnetically quiet conditions according to data from the ionospheric Tixie Bay station and DMSP satellites

The paper analyzes experimental data on the position of the polar wall of the main ionospheric trough under low geomagnetic activity at Kr=0–1 from measurements made at the Yakutsk chain of vertical and oblique sounding ionosondes. The northern boundary of the trough under these conditions shifts to high magnetic latitudes 67–70°. This corresponds to the position of the geophysical structure “contracted oval” or compressed oval. Critical frequencies at the polar wall of the trough have high values ​​of about 6–8 MHz. At this time, the DMSP satellite records intense 200–300 eV electron precipitation that can create the observed ionization in the F-region of the ionosphere.