Predicting Equatorial F-Region Instabilities and the Prereversal Enhancement using WAM-IPE

A regional physics-based model is used to reproduce ionospheric irregularities in the equatorial F region associated with Equatorial Spread F. Results from the simulation are verified using radar observations from the Jicamarca Radio Observatory. The simulation is run in two modes which differ in their initialization and forcing methods. The first mode uses a combination of ionospheric parameter estimations from Jicamarca ISR observations and empirical models. When run in this mode, the model has been shown to reliably reproduce the presence or absence of irregularities. The second mode is initialized and forced using parameters from the global atmosphere, ionosphere, plasmasphere model, WAM-IPE. The daily accuracy of the model when driven with WAM-IPE parameters is highly dependent on the daily accuracy of vertical plasma drifts. In particular, the timing and magnitude of the prereversal enhancement seem to be most important. The prereversal enhancement is closely correlated with the occurrence and strength of spread F events, so predicting its day-to-day variability is necessary for forecasts of the day-to-day occurrence of equatorial spread F. Examples are shown of cases when WAM-IPE vertical drifts diverge from observations and therefore drive different results in the regional model. A simplified, local, two-dimensional field-line integrated electrodynamics model is used as a proxy to WAM-IPE to study the impact that certain parameters have on the resulting electric fields. The parameters tested in this study include the magnitude and phasing of the neutral thermospheric winds, and ion compositions.