Fig. 2From: Role of hard X-ray emission in ionospheric D-layer disturbances during solar flaresTime profiles for several flares of increasing strength (column) and GQD, NRK and NSY (from top to bottom row). Vertical dashed lines indicate the flare peak time (as given by the GOES daily reports). Amplitudes are given in arbitrary units. NRK was off-air for the X1.1 flare, while NSY was off-air during the X2.2 and X9.3Back to article page