- University of Bergen, Dept. of Physics and Technology, Bergen, Norway (karl.laundal@ift.uib.no)
Large-scale magnetosphere-ionosphere coupling has traditionally been described as a 2D electric circuit, where an electrostatic ionospheric electric field is inferred from prescribed field-aligned currents and ionospheric conductivity. Low-latitude regions are often treated separately, driven primarily by neutral winds. This conventional approach neglects magnetic induction and only accounts for steady states, without addressing how transitions between states occur. We propose an alternative approach in which the ionosphere responds dynamically to an imposed magnetic field, governed by Faraday's law. The imposed magnetic field is derived from prescribed field-aligned currents at high latitudes and constraints on inter-hemispheric symmetries at low latitudes. Simulation results demonstrate that the ionosphere takes several tens of seconds to adapt to variations in the imposed magnetic field, capturing dynamic processes absent in conventional models. Our simulations incorporate neutral winds, realistic magnetic field geometries, and horizontal variations in ionospheric conductivity. The model describes both the dynamic high-latitude magnetosphere-ionosphere coupling and how Sq currents and the so-called penetration electric field are established. To our knowledge, this is the first detailed description of these phenomena in terms of magnetic induction.
How to cite: Laundal, K. M., Skeidsvoll, A., P. Braileanu, B., Hatch, S., Madelaire, M., and T. Kebede, F.: A new model for global inductive magnetosphere-ionosphere-thermosphere coupling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12818, https://doi.org/10.5194/egusphere-egu25-12818, 2025.