Ionospheric density oscillations associated with recurrent prompt
penetration electric fields during the space weather event of 04
November 2021 over the East-Asian sector
Abstract
We found the signatures of the multiple prompt penetration electric
fields (PPEF) and the disturbance dynamo (DD) 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 03-05 November 2021. The observation is made on
GPS-TEC, digisonde, and magnetometer stations. In the main phase of the
storm, intense modulations of VTEC (vertical total electron content) and
foF2 (critical frequency) are observed as coherently fluctuating with
IEF (interplanetary electric field) and IMF Bz reorientations. It is
diagnosed that the oscillations in the DP2 (disturbance polar current 2)
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
~1hr. This result suggests that the wavelike
oscillations of VTEC and foF2 and H component are associated with PP
electric fields.