Simulation Study of the 15 January 2022 Tonga Event: Development of Super Equatorial Plasma Bubbles.

We present high‐resolution simulation results of the response of the ionosphere/plasmasphere system to the 15 January 2022 Tonga volcanic eruption. We use the coupled Sami3 is Also a Model of the Ionosphere ionosphere/plasmasphere model and the HIgh Altitude Mechanistic general Circulation Model whole atmosphere model with primary atmospheric gravity wave effects from the Model for gravity wavE SOurces, Ray trAcing and reConstruction model. We find that the Tonga eruption produced a "super" equatorial plasma bubble (EPB) extending ∼30° in longitude and up to 500 km in altitude with a density depletion of 3 orders of magnitude. We also found a "train" of EPBs developed and extended over the longitude range 150°–200° and that two EPBs reached altitudes over 4,000 km. The primary cause of this behavior is the significant modification of the zonal neutral wind caused by the atmospheric disturbance associated with the eruption, and the subsequent modification of the dynamo electric field. Plain Language Summary: The Hunga Tonga‐Hunga Ha'apai volcanic eruption occurred on 15 January 2022 at 04:14 UT and generated a massive atmospheric disturbance that caused major effects in the ionosphere worldwide. Using a high‐resolution coupled ionosphere/thermosphere model we show that the changes in the thermospheric winds strongly modified the electrodynamics of the ionosphere. This led to the development of a "train" of equatorial plasma bubbles (EPBs), regions of very low electron density, in the western Pacific sector. Moreover, two EPBs reached unusually high altitudes, over 4,000 km. Key Points: Modeling of the Tonga volcanic eruption show equatorial plasma bubbles (EPBs) develop in the Pacific sectorA large equatorial bubble formed below 500 km roughly 30° in longitudeEPBs rose to very high altitudes (>4,000 km) [ABSTRACT FROM AUTHOR]