Fig. 5
From: Continuous Doppler sounding of the ionosphere during solar flares
Electron density gradient and electron density changes. a Electron density gradient as a function of plasma frequency, b fluctuations of reflection heights calculated by Eq. (4) for f = 7.04, 4.65, and 3.59 MHz by black, red, and blue, respectively, c electron density change ΔN calculated by Eq. (7) at the reflection heights for f = 7.04, 4.65 and 3.59 MHz by black, red, and blue, respectively. d Relative electron density change related to the electron density at 14:00 UT on 22 October 2014 (Fig. 3d)