GEM: Modeling the Altitude Profile of Auroral Ion Heating in Return Current Regions

University Of New Hampshire, Durham NH

Investigators

Abstract

One of the major deficiencies of current global magnetohydrodynamics (MHD) models of the magnetosphere is the fact that they do not properly treat the energization and outflow of ions from the ionosphere. Ion outflow becomes particularly important during magnetic storms. This project will develop a model for the outflow of ions from the ionosphere into the magnetosphere. The project is a further development of a model derived from Fast Auroral SnapshoT (FAST) satellite data that allows one to estimate the altitude of the double layer in return current regions. The model makes it possible to determine how the electron and ion distributions vary along the magnetic field line. The project will investigate how the heating of the ion distribution functions varies with altitude and how the heating rate profile depends on magnetospheric inputs such as parallel current and Poynting flux. The model requires some assumptions to close the fluid equations and the project will check the validity of those assumptions by comparing the model prediction to data available at the Polar satellite when that satellite is in magnetic conjunction with the FAST satellite. The closure conditions will also be validated by comparing the model results with the FAST data in a statistical way. The results of these investigations will then be used to construct a code module of auroral ion outflow that will be incorporated into the OpenGGCM global MHD model. The broader impacts of the project include the fact that the leader of the project is a young scientist. There are also educational impacts because the project will support research by a graduate student. Finally, the module that will be developed has the potential to be incorporated in other global models of the magnetosphere which will aid in the development of a Geospace General Circulation Model (GGCM) that may be used in space weather forecasting.