Ionospheric Density Oscillations Associated With Recurrent Prompt Penetration Electric Fields During the Space Weather Event of 4 November 2021 Over the East‐Asian Sector

We found the signatures of the multiple prompt penetration electric fields and the disturbance dynamo electric field having impacts on the East Asian sector ionosphere along the meridional chain thoroughly from the equator, low-mid to high latitudes during the space weather event of 3-5 November 2021. The observation is made on global positioning system-total electron content (GPS-TEC), digisonde, and magnetometer stations. In the main phase of the storm, intense modulations of vertical total electron content (VTEC) and critical frequency (foF2) are observed as coherently fluctuating with interplanetary electric field (IEF) and IMF Bz reorientations. It is diagnosed that the oscillations in the disturbance polar current 2 (DP2) current system directly penetrate meridianally from high to equatorial latitudes, leading to the significant changes in ionospheric electrodynamics that governs the density fluctuations. The wavelet spectra of VTEC, foF2, h'F (virtual height), H-components and IEF give a result of common and dominant periodicity occurring at similar to 1 hr. This result suggests that the wavelike oscillations of VTEC and foF2 and H component are associated with prompt penetration electric fields.