Low Latitude Plasma Bubble Growth Rates During the September 2017 Geomagnetic Storm

Abstract:

The geomagnetic storm of September 7-9, 2017 occurred during an interval of enhanced solar activity resulting in multiple flares, several coronal mass ejections (CMEs), and a number of space weather-related phenomena. During this time period, multi-instrument observations showed numerous periods of occurrence of equatorial and mid-latitude plasma irregularities and bubbles. We present results from using numerical simulations with the coupled SAMI3/RCM first-principles model to understand ionospheric storm-time electrodynamics. We use simulations results to estimate linear growth rates of the generalized Rayleigh-Taylor instability, specifically examining the role of prompt penetration electric fields. Calculated growth rates will be compared to multi-instrument observations of equatorial plasma irregularities made by the FPMU instrument suite (on board the International Space Station), the SWARM spacecraft, and total electron content (TEC) derived from ground-based GNSS receivers. Electric field results will be compared to electric field (drift velocity) measurements by the Jicamarca and the Millstone Hill incoherent scatter radars, and topside plasma densities and drift velocities by the DMSP spacecraft. By comparing calculated growth rates to plasma bubble occurrence, we can examine the role of storm-time electric fields in plasma bubble formation.