Lauren Orr

The Space Weather Instrumentation, Measurement, Modelling and Risk: Thermosphere (SWIMMR-T) programme aims to improve the UK’s ability to specify and forecast the thermosphere. AENeAS (Advanced Ensemble electron density [Ne] Assimilation System) is a physics-based, thermosphere-ionosphere, coupled, assimilative model, which makes possible thermospheric forecasts. Currently AENeAS uses the Heelis and Weimer electric field spacecraft climatology models but it is possible a more recent electric field model will improve its functionality. The new models include three statistical models for ionospheric convection using line-of-sight velocity measurements from the Super Dual Auroral Radar Network (SuperDARN): Thomas and Shepherd (TS18), the Time-Variable Ionospheric Electric Field model (TiVIE) and the empirical orthogonal functions (BAS EOF) model. Before implementation in AENeAS, we first compare the new SuperDARN-based models to the established spacecraft climatology models.

Here we present quantitative comparison of the electric-field models across a variety of geophysical conditions, including during storm times. To allow for fair comparison between models we explore methods of standardizing the input parameters using pre-existing equations. Once standardized, each model’s ionospheric convection patterns can be compared for varying solar wind and interplanetary magnetic field (IMF) conditions. We explore the relationships between the IMF conditions and model output parameters such as the polar cap transpolar voltage and size. During storms we compare the parameterized model output time series from the different electric field models, including the commonly used SuperDARN Map Potential Model. At peak storm times we find the calculated electric potential magnitude to be much greater from the spacecraft-based models. We will discuss the similarities and differences found using each method.