Electron Precipitation Models in Global Magnetosphere-Ionosphere Simulations

Friday, 19 December 2014: 8:15 AM
Binzheng Zhang1, William Lotko1, Oliver Brambles2, Michael James Wiltberger3 and John Lyon1, (1)Dartmouth College, Hanover, NH, United States, (2)Thayer School of Engineering, Hanover, NH, United States, (3)National Center for Atmospheric Research, High Altitude Observatory, Boulder, CO, United States
The ability to forecast the weather of the geospace environment depends critically on the ability to accurately model the dynamics of the magnetosphere-ionosphere (MI) system. Global simulations play an important role in understanding the coupled MI system. A key feature of most global models is the implementation of magnetosphere-ionosphere (MI) coupling, and electron precipitation is one of the most important processes to specify. However, one deficiency of most global simulation codes is the lack of accurate specifications of electron precipitation. The principle objectives of the study are to improve the existing diffuse and monoenergetic electron precipitation model and to implement broadband and cusp electron precipitation models. The diffuse electron precipitation model is improved by introducing a dynamically regulated boundary. Broadband electron precipitation is regulated by the downward AC Poynting flux, together with empirical relations derived from satellite data. Cusp electrons are specified based on a cusp identification algorithm used in the global simulation. The improved electron precipitation patterns show reasonable agreement with an empirical model, and the simulated hemispheric power shows agreement with satellite observations during event simulations.