The Simulation of the Ionospheric Current System and Its Impact on the Earth’s Magnetic Field

Thursday, 26 May 2016
Boris E. Prokhorov1, Matthias Foerster1, Vincent Lesur2, Alexander A Namgaladze3, Matthias Holschneider4 and Claudia Stolle1,4, (1)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany, (2)Institut de Physique du Globe de Paris, Paris, France, (3)Murmansk State Technical University, Murmansk, Russia, (4)University of Potsdam, Potsdam, Germany
Abstract:
The system of the ionospheric current is a part of the global magnetospheric electrical chain. In this electrical chain, the currents are generated by the solar wind and Interplanetary Magnetic Field (IMF) interaction with the Earth’s magnetosphere. Those currents are transferred to the ionosphere of the Earth via the Field Aligned Currents (FACs) and define the electrodynamics of the coupled Magnetosphere – Ionosphere – Thermosphere (MIT) system.

For this study, we perform the modelling of the dynamic ionospheric current system. Those simulations are done with an improved version of the first-principle, time-dependent, and fully self-consistent numerical global Upper Atmosphere Model (UAM-P). This model describes the thermosphere, ionosphere, plasmasphere and inner magnetosphere as well as the electrodynamics of the coupled MIT system for the altitudinal range from 80 (60) km up to the 15 Earth radii. The equatorial and lower latitudinal ionosphere of this model was improved for the present investigation.

Additionally, we calculate the contribution of the ionospheric currents to the Earth’s magnetic field. For this purpose, we obtain the additional magnetic field from the system of the ionospheric currents calculated with the UAM-P model. The magnetic field generated by the ionospheric currents is calculated using the Biot-Savart law. The ionospheric impact on the magnetic field is significant at dayside and high-latitudinal regions, where maximum values of these currents occur. The additional magnetic field of ionospheric origin depends on the geomagnetic conditions and has significant seasonal and UT variations.

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