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

Abstract

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.