Storm-time dynamic Alfvén layers: Testing electric and magnetic field models

The mapping of ionospheric electric potential along magnetic field lines is applied to Weimer [2005. Improved ionospheric electrodynamic models and application to calculating Joule heating rates. Journal of Geophysical Research 110, A05306] electric field model in dipole and TS04 magnetic field models during 7/8 November 2004 magnetic storm. The particle motion in field models is studied in order to determine the possible region of aurora occurrence. Comparison of the Alfvén layers with oval boundaries observed by TIMED/GUVI is a test for applicability of the models for the storm-time conditions. Qualitative agreement with expectations is obtained, with the indication of penetration electric fields. Prediction of the oval boundary position is not achieved so far. Additionally, the TS04 model predicts strong partial ring current and probably unrealistic X-line. Magnetic field measurements by GOES-12 show the current to be much more variable than the modeled one.