Modeling Sudden Stratospheric Warming Events Using the Ionosphere-Plasmasphere-Electrodynamics (IPE) Model

Sudden Stratospheric Warming (SSW) events are large meteorological disturbances where the northern winter stratospheric westerly winds slow down or reverse direction. The perturbation is associated with a breakdown in the northern polar vortex and has been observed to cause various anomalies in the upper atmosphere. SSW events occur nearly every year to varying degrees of strength. Understanding the connection between the terrestrial and space weathers during these events has become more important with increased solar activity, particularly in an effort to separate out forcing from the events and from geomagnetic and solar activities. In this work, the Ionosphere-Plasmasphere Electrodynamics (IPE) model is used to investigate the response of the ionosphere during SSW events. The Jicamarca 150km echo observation is used to describe the main ionospheric forcing during the SSW event. The IPE model reproduces the observed ionospheric response to the large SSW event of January 2009. Our results illustrate the direct impact of the equatorial drift deviations during the SSW event on the variations of main ionospheric parameters. Furthermore, we evaluate the role of the coupling between ionosphere and plasmasphere during the solar minimum in reproducing the observations. The global drift from Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIMEGCM) is also used to evaluate the role of the latitudinal and local time variations of the ExB drift. Finally, we compare the ionospheric responses between 2009 and 2013 to understand the different ionospheric responses depending on the solar flux conditions.