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

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.