Investigating Correlations Between Day-to-Day Variability in Pre-Reversal Enhancement in Equatorial Electron Drifts and Neutral Winds

The pre-reversal enhancement (PRE) of the equatorial zonal electric field arises from the F-layer neutral wind dynamo and is a driver of equatorial spread-F. Yet, the drivers of the PRE's day-to-day variability remain uncertain. We investigate the altitude- and local-time-dependent sensitivity of the daily variability of the PRE to neutral wind perturbations using observations from the Ionospheric Connection Explorer (ICON) and simulations with WACCM-X. We present correlation studies to identify local times and altitudes of neutral winds that may drive day-to-day variability in PRE. ICON orbits separated by 24 ± 0.25 hours are paired to minimize longitudinal effects and to isolate short-term changes in PRE strength and neutral winds. WACCM-X simulations reveal alternating-sign correlations between PRE variability and E-region zonal neutral winds, with positive correlations near ~90–110 km, negative correlations near ~120–150 km, and weakly positive correlations above ~180 km, most pronounced near sunset. Observations exhibit a similar but weaker structure. In contrast, F-region winds above ~150 km show predominantly weakly positive correlations in WACCM-X and limited coherence in observations.