Performance of Equatorial Electrodynamics for WAM-IPE during Geomagnetic Storms

The coupled Whole Atmosphere Model - Ionosphere Plasmasphere Electrodynamics (WAM-IPE) is an operational space-weather prediction model by National Oceanic and Atmospheric Administration Space Weather Prediction Center (NOAA-SWPC). The high-latitude convections in the model are currently driven by the Weimer empirical model based on the solar wind parameters. In this study, several high-latitude drivers, including Michigan Geospace Model (MGM), Assimilative Mapping of Geospace Observations (AMGeO) and Weimer 2005 empirical model, are tested in WAM-IPE in order to determine the best simulations that capture the storm-time ionospheric responses at equatorial region. Simulations during the 2015 St. Patricks Day geomagnetic storm are carried out. It has been observed that the Geospace model provides the most intense electric field as well as the highest latitudinal penetration among all these models. Upward EB drifts from Geospace driven WAM-IPE at Jicamarca (11.95S, 76.87W geographic; 2.21S, 4.17W geomagnetic) are compared with that from Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere (JULIA) and Prompt Penetration Equatorial Electric Field Model (PPEEFM1) on March 17-18, 2015. It has been observed that the effects of night-time Prompt Penetration Electric Field (PPEF) are well-captured by WAM-IPE. But the magnitudes of the corresponding downward E×B drifts are overestimated compared to values from PPEEFM1 model. The comparisons between global WAM-IPE Total Electron Content (TEC) and GNSS TEC on March 17, 2015 have shown that the general features of the TEC variations are well captured by the model with some overestimation at the Equatorial Ionization Anomaly (EIA) region.