Characterization of the ionosphere response to the X1.3 solar event occurred on 30 March 2022

This work aims to characterize the ionospheric disturbances in the South America – Antarctic Peninsula sector due the impact of a X1.3 solar event. This flare occurred on 30 March 2022 strongly impacted the upper atmosphere, producing a short-wave fadeout of ∼50 min duration. The solar flare impact on ionospheric conditions, at different latitudes, the ionospheric currents were evaluated from the horizontal component (ΔH) of the surface magnetic field, the electron density from cosmic noise absorption (CNA) obtained with riometers, ionosonde parameters of F and E regions, and vertical total electron content (VTEC) and rate of VTEC (ROT). The results showed that this intense center disk flare, with no late phase EUV enhancement, mostly impacted the electron density on the E and D regions of the ionosphere, with no significant effects observed on the F region. But a decrease in the F region height at near equatorial stations was observed during the flare maximum, which suggests a weakening of the fountain effect. A blanketing in the E region was observed, which occurred during the flare fluxes at X-ray and EUV were at high levels, in close temporal association with a short-wave fadeout observed with the South America e-CALLISTO at Arecibo, and a HF signal attenuation observed with the SuperDARN radar at Falkland Islands at high latitude. An interesting result refers to the surface magnetic field variation (ΔH), which showed ionospheric currents intensification in close association with the Sq currents in the E region at distinct latitudes during the rising X-ray and EUV fluxes of the solar flare; but during solar flare decay, when the X-ray and EUV >100 nm fluxes were still high, they showed a different behavior from Sq currents, suggesting that at this time the ionospheric currents were due the solar flare effect (SFE) acting in the D region. The suggested weakening of the fountain effect is reinforced by the EEJ complex behavior observed during the solar flare, which might be attributed to a decrease on the eastward EEF. These results show that the flare impact on the ionosphere was a combined effect of local photoionization and global electrodynamical processes.

Details