Abstract
This study reveals the geomagnetic storm-induced ionospheric perturbations observed over the near-equatorial Indian stations - Cochin and Changanacherry in 2021. The 205 MHz VHF radar at Cochin University of Science and Technology (CUSAT) detected the storm-induced E- and F- region echoes during the moderate (28th February − 6th March 2021) and weak (19th − 25th March 2021) storm events. The fast-fluctuating northward interplanetary magnetic field (IMF BZ) and inhibition of the equatorial ionization anomaly (EIA) observed on 1st March indicate the suppression of daytime eastward electric field by the westward electric field associated with the counter electrojet (CEJ). Concurrent equatorward shift in the EIA crest and minor positive storm enhancement in the vertical total electron content were observed. The CEJ could have helped in the accumulation of photo-generated plasma at the near-equatorial region by pushing the daytime F-layer downward. During the moderate storm phase, post-sunset E-region echoes were detected during 1st − 3rd March, attributed to the disturbance dynamo electric field (DDEF). Nevertheless, during the main phase of the weak storm, a poleward shifting of the EIA crest occurred on 20th March, indicating the presence of a prompt penetration electric field (PPEF), which enhanced the upwardE×Bdrift. A major positive ionospheric storm enhancement that lasted for 7 h occurred on 20th March due to the DDEF. Bottom-type F-region echoes were observed over Cochin during the recovery phase of the weak storm. This work highlights the observation of equatorward and poleward shifting of the EIA using a 205 MHz radar.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call