Modeling Equatorial Plasma Bubbles With SAMI3/WACCM‐X: September 2017 Storm

Abstract

Abstract We report results from a global simulation of the September 2017 geomagnetic storm. The global model comprises the ionospheric code SAMI3 and the atmosphere/thermosphere code WACCM‐X. We show that a train of large‐scale EPBs form in the Pacific sector during the storm recovery phase on 8 September 2017. The EPBs are associated with storm‐induced modification of the zonal and meridional winds. These changes lead to an eastward electric field which in turn causes an upward E × B drift in the post‐midnight sector. A large decrease in the Pedersen conductance caused by meridional equatorward winds leads to an increase in the growth rate of the generalized Rayleigh‐Taylor instability that causes EPBs to develop. Interestingly, several EPBs reach altitudes above 3,000 km.

Keywords

• geomagnetic storms
• stormtime winds
• disturbance dynamo
• equatorial plasma bubbles