The response of ionospheric outflow to various types of high latitude auroral precipitation

Solar ultraviolet (UV) photons and auroral precipitation are two significant energy inputs important to understanding the topside ionosphere and ion upflows and outflows. UV photons heat and ionize the upper atmosphere and lead to the generation of the superthermal photoelectron population. Particle precipitation, caused by the dynamics associated with the solar wind interaction with the Earth's magnetic field, leads to ionization and secondary electron production as well as the deposition of significant amount of energy from the magnetosphere into the ionosphere. The role of these mechanisms in the cause ionospheric upflow and outflow is studied in this presentation.

To understand the effects of various classes of auroral precipitation on the outflow problem, we have selected the June 6, 2013 GEM challenge event for our analysis. The OVATION Prime 2013 (OP-13) model data representing the energy and number flux of the precipitating electron population was obtained in 5-min cadence for this event. For the first time, the particle precipitation output of the OP-13 model was utilized to drive the Polar Wind Outflow Model (PWOM) for studying the ionospheric outflow. PWOM solves the transport of plasma from the ionosphere to the magnetosphere along a single expanding flux tube in a region confined between 200 km to a few Earth radii. For this event, we have simulated the motion of a single flux tube (magnetic field line) through the high latitude/polar region, studied how the plasma on this flux tube is exposed to different auroral inputs and solar illumination over time and the corresponding response of the ionosphere. Specifically, we will present and discuss the results of this storm time case study and compare the results with simulations of the same event in the absence of thermospheric changes.