Fig. 10
From: Continuous Doppler sounding of the ionosphere during solar flares
X-ray events on 7 August 2016 and their ionospheric responses. a X-ray fluxes in the ranges 0.1–0.8 nm and 0.05–0.4 nm by red and blue, respectively, recorded from 14:30 to 15:30 UT. b Time derivatives of the X-ray fluxes, dFX/dt, (red for 0.1–0.8 nm, blue for 0.05–0.4 nm). c Spectrogram recorded by CDSS in Tucumán from 14:30 to 15:30 UT. d Virtual plasma velocity u *P obtained by Eq. (3) for f = 4.63 MHz