Modelling the ionospheric response to solar variability with TIE-GCM and CTIPe

Kurzfassung

Solar EUV radiation is the main driver of ionization processes in the upper atmosphere and its variability on different timescales significantly impacts the variations of the ionospheric plasma. Previous analyses of this response observed a delayed reaction of the ionosphere to solar EUV variability with 1-2 d. The physical and chemical processes causing this ionospheric delay are under investigation (e.g. slow diffusion of oxygen, transport processes or composition changes) and their respective contributions have to be discussed. This study further analyzes the delayed ionospheric response to solar EUV radiation using results of long-term simulations with two physics-based global 3-D models, the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) and the Coupled Thermosphere-Ionosphere Plasmasphere electrodynamics (CTIPe) model. The setup, similarities and differences of the model calculations are presented and the performance of the models is discussed by comparison to measurement data of the Total Electron Content (TEC) and other ionospheric parameters (e.g. F2 layer peak electron density). Finally, the results are used to characterize the delayed ionospheric response to solar variability.