Fig. 3
From: EUV signals associated with O+ ions observed from ISS-IMAP/EUVI in the nightside ionosphere
Time profile of the averaged EUV count over the pixels surrounded by the red square in Fig. 1 (blue) during the period from 21:02 UT to 21:25 UT on December 26, 2012. The total electron content (TEC) value at the ISS location (orange) and that at the tangential point along the line of sight (green) are also plotted for reference. The horizontal axis indicates the universal time (UT) and the local time (LT) at the position of the ISS