A STORM TIME ASSIMILATIVE MAPPING OF IONOSPHERIC ELECTRODYNAMICS ANALYSIS FOR THE SEVERE GEOMAGNETIC STORM OF NOVEMBER 8-9, 1991

Global parameters are obtained for the November 8-9, 1991 severe geoma gnetic storm with the application of a slightly modified version of th e Assimilative Mapping of Ionospheric Electrodynamics (AMIE) data inve rsion model. Inputs to the model include ground magnetometer data, sat ellite electron precipitation data, satellite ion drift data, and ion drift velocities obtained from radar measurements. We compare two of t he AMIE computed parameters the total Joule heating and the polar cap potential, to both the AE(12) index and the AE(AMIE) index, an AMIE mo deled AE index created specifically for severe storm times. The equati on obtained from a linear fit to the total Joule heating versus the AE (AMIE) index closely resembles other equations found during much less disturbed times using the AE(12) index. Our results using the AE(12) i ndex appear to saturate at a level around 1300 nT. However, this satur ation is associated with the calculation of the AE(12) index and not a physical result. An apparent saturation can also be seen in our compa rison of the polar cap potential with the AE(12) index, but this is no t the case when using the AE(AMIE) index. The comparison between the p olar cap potential and the AE(AMIE) index yields an approximate linear relationship with a correlation coefficient of 0.80. From our results , we find that the magnitude of the auroral electrojets and the polar cap potential drop do not show signs of saturation at the activity lev els that were present during the November 8-9 1991 severe storm.