Extreme poleward expanding super plasma bubbles triggered by Tonga volcano eruption during the recovery phase of geomagnetic storm | CU Experts

The Tonga volcano eruption of 15 January 2022 unleashed a variety of; atmospheric perturbations, coinciding with the recovery phase of a; geomagnetic storm. The ensuing thermospheric variations created rare; display of extreme poleward-expanding conjugate plasma bubbles seen in; the rate of total electron content index (ROTI) over 100-150°E. This is; associated with fluctuations in FORMOSAT-7/COSMIC-2 (F7/C2) ion-density; measurements and spread-F signatures in ionograms, reaching; ~40°N geographic latitude. This was preceded by an; unusually strong pre-reversal enhancement (PRE) in the global; ionospheric specification (GIS) electron density profiles derived from; F7/C2 observations. The GIS further revealed a decrease of equatorial; ionization anomaly (EIA) crest density due to the storm impact. A sharp; decrease of E-region conductivity by volcano-induced waves, combined; with enhanced F-region wind over EIA with less ion-drag apparently; intensified the PRE. The strong PRE and seed perturbations from the; volcano-induced waves likely further triggered super plasma bubble; activity.

Rajesh PK; Lin CCH; Lin J-T; Lin C-Y; Liu J-Y; Matsuo T; Huang C-Y; Chou M-Y; Yue J; Nishioka M

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