Fig. 10

The longitude–latitude maps of electron density at an altitude of 300 km obtained from the F7/C2 GIS data during 0930–1230 UT. a–d The average electron density during previous 5 days as reference. e–h The electron density on 18 October 2020. i–l the difference between the two. The white dotted line denotes the geomagnetic equator and the shaded region corresponds to post-sunset period. The latitude profiles of electron density at selected periods of 1030 and 1130 UT at 120 E longitude on 18 October 2020 are shown in n and p to compare the PRE on this day with that on the reference day in m and o