Improved horizontal wind model HWM07 enables estimation of equatorial ionospheric electric fields from satellite magnetic measurements

摘要

Horizontal neutral winds play an important role in low-latitude ionospheric E and F-region dynamics. In particular, the zonal winds have strong effects on the local structure of the low-latitude ionospheric current system. Accurate wind specification is therefore essential for modeling these currents. In order to investigate the retrieval of eastward electric fields from satellite-derived equatorial electrojet (EEJ) profiles, we consider a provisional Horizontal Wind Model (HWM07) and its implications for the meridional structure of the EEJ. We find that EEJ current profiles predicted using HWM07 agree better with CHAMP magnetometer-derived current profiles than EEJ profiles predicted using the older HWM93 model. The improved wind model opens exciting new possibilities of determining the day-side eastward electric field in the equatorial ionosphere from satellite magnetic field measurements.