Comparing the cross polar cap potentials measured by SuperDARN and AMIE during saturation intervals

Abstract

Assimilative Mapping of Ionospheric Electrodynamics (AMIE) and Super Dual Auroral Radar Network (SuperDARN) are two commonly used techniques to measure cross polar cap potential (PC). In this study, I compare PC inferred from AMIE with that inferred from SuperDARN during saturation intervals. Measurements from Defense Meteorological Satellite Program (DMSP) and polar cap (PC) index are also used to help estimate true PC. Seven saturation events in 2000 were selected. For each event, I ran the AMIE software driven by magnetometer data only, by magnetometer data and SuperDARN data, and by SuperDARN data only. Then I compared PC obtained from AMIE with that from SuperDARN. I found that: (1) PC inferred from SuperDARN is significantly lower than that inferred from other techniques including AMIE when PC is large (e.g., greater than 150kV); (2) PC inferred from AMIE with SuperDARN input is much higher than PC inferred from SuperDARN; (3) PC inferred from AMIE with magnetometer input tends to give the same results as that inferred from AMIE with magnetometer and SuperDARN input; (4) PC inferred from AMIE with magnetometer input is, in general, in agreement with PC inferred from AMIE with SuperDARN input. It is suggested that reason for the low values of SuperDARN-derived PC during saturation intervals is that the SuperDARN algorithm to compute PC from measurements is not applicable to such intervals. © 2012. American Geophysical Union. All Rights Reserved.