Speaker
Description
The ionosphere is a highly complex plasma containing electron density structures with a wide range of spatial scale sizes. The ionosphere is coupled to the Earth’s magnetosphere and the solar wind, as well as to the neutral atmosphere. Variability within the ionosphere is highly dependent on the driving processes. Thus, modelling the ionosphere and capturing its full dynamic range considering all spatiotemporal scales is challenging.
Swarm is the European Space Agency’s (ESA) first constellation mission for Earth Observation (EO), comprising multiple satellites in Low Earth Orbit (LEO). During the Swarm-VIP-Dynamic project, a suite of statistical models has been developed using observations from Swarm and proxies for heliogeophysical processes. Models have been developed for the electron density and the variability in the ionospheric plasma at spatial scales between 100 km and 7.5 km. At the larger spatial scales, the model performance approaches the theoretical best values when appropriate measures of solar activity, the solar wind and the thermospheric density are included in the models. The model performance decreases at smaller spatial scales, suggesting that a physical process is missing from the models. Possible candidates are instability processes or driving by wave activity from the lower atmosphere, neither of which are captured by the models. It would be possible to trial proxies for wave activity in a future development of the models.
The performance of the Swarm-VIP-Dynamic electron density models and the Thermosphere-Ionosphere- Electrodynamics General Circulation Model (TIE-GCM) are compared. There are substantial biases in TIE-GCM which are not present in the Swarm-VIP-Dynamic models. It would be possible to use the Swarm-VIP-Dynamic models to calibrate TIE-GCM to remove these biases. The steps which would be needed for such an implementation are discussed.
