Fig. 7
From: Continuous Doppler sounding of the ionosphere during solar flares
Estimating attenuation in the Czech Republic on 22 October 2014. Solid lines represent modeled values before solar flare event at 14:00 UT and dashed lines the values during solar flare event a electron–neutral collision frequency ν/(2π) as a function of height. b Electron density as function of height. c Imaginary part of wave vector as a function of height for B = 0 and f = 7.04 MHz (black) and f = 4.65 MHz (red). d Cumulative attenuation A in dB considering propagation up and down for f = 7.04 MHz (black) and f = 4.65 MHz (red)