Abstract We investigate the ionospheric and geomagnetic responses to an M7.4‐class early impulsive solar flare that occurred on 10 March 2024 using Global Positioning System (GPS), ground‐based magnetometer, and ionosonde observations. Ionospheric perturbations were examined using Total Electron Content (TEC) and the rate of change of TEC (ROT) derived from GPS data. VTEC and ROT variations were observed at all low‐, mid‐, and high‐latitude regions, and maximum values were found at low latitudes (0.89 TECu and 0.76 TECu/min respectively). Flare's early hard component does not affect VTEC, as it is primarily contributed by the upper ionosphere. Geomagnetic effects were analyzed using magnetometer data with both 1 s and 1 min temporal resolutions. Clear perturbations in the horizontal geomagnetic field (ΔH) were detected at all equatorial, low‐, and mid‐latitude stations but less distinct for a high latitude station. High‐resolution (1 s) data reveal two temporally distinct ΔH signatures: a short‐duration (90–95 s) early impulsive peak/dip due to the hard/gamma component of flare, referred to here as the Crochet Impulsive Component (CIC), and a longer‐lasting response (∼20 min) associated with the soft X‐ray driven Solar Flare Effect. The CIC occurred within 1 min of the peak hard X‐ray/gamma ray emission. At two low‐latitude stations, VSS and HBK, the ΔH peak was observed nearly simultaneously with the soft X‐ray peak. Ionosonde observations over the Brazilian sector further indicated a complete radio blackout during flare. TEC variations are driven by EUV/soft X‐rays, while early impulsive hard emissions produce rapid geomagnetic disturbances detectable in high‐resolution data.
Tripathi et al. (Wed,) studied this question.