ION CONVECTION AND ITS IMPACTS ON THE THERMOSPHERIC WINDS FROM THE TIEGCM SIMULATION IN THE SOUTHERN POLAR CAP REGION

One of the salient features of the polar ionosphere is the plasma convection, which is driven by magnetospheric forcings. The magnetospheric energy inputs to the high-latitude ionosphere are transferred to the thermosphere via ion-neutral collisions, and can modify the thermospheric neutral wind patterns. In the previous study, we analyzed the measurements of neutral wind and ion drift achieved by simultaneous ground-based observations in the southern polar cap, and investigated the effects of the ion drifts on the neutral winds. We also utilized NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) to compare with the measurements of the high-latitude ion and neutral convections. TIEGCM simulation results with default settings exhibited large discrepancies from the observations for both the neutral winds and ion drifts, but the most noticeable difference was found in the ion drifts; the TIEGCM substantially underestimated them. Before identifying the discrepancies in the responses of the neutral winds to the ion drifts between the observation and model, we first attempt to adjust forcing factors to determine the ion drifts within TIEGCM to minimize the model-observation differences. In this talk the results of the study will be presented with discussions in association with corresponding thermospheric winds.