Blar i Department of Physics and Technology på forfatter "Ohma, Anders"
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Spatial Resolution in Inverse Problems: The EZIE Satellite Mission
Madelaire, Michael; Laundal, Karl Magnus; Gjerloev, J.; Hatch, Spencer Mark; Reistad, Jone Peter; Vanhamäki, H.; Waters, Colin; Ohma, Anders; Mesquita, Rafael L. A.; Merkin, Viacheslav (Journal article; Peer reviewed, 2023)Inverse modeling has become one of the primary methods for studying ionospheric electrodynamics, especially when using magnetic field measurements from below the ionosphere. We present a method for quantifying the spatial ... -
Statistical Temporal Variations in the Auroral Electrojet Estimated With Ground Magnetometers in Fennoscandia
Walker, Simon; Laundal, Karl Magnus; Reistad, Jone Peter; Ohma, Anders; Hatch, Spencer Mark (Journal article; Peer reviewed, 2023)We present the implementation of an improved technique to coherently model the high-latitude ionospheric equivalent current. Using a fixed selection of 20 ground magnetometers in Fennoscandia, we present a method based on ... -
Substorm Impact on Dayside Ionospheric Currents
Elhawary, Reham Zakaria Ahmed Mohamed; Laundal, Karl Magnus; Reistad, Jone Peter; Madelaire, Michael; Ohma, Anders (Journal article; Peer reviewed, 2023)Ionospheric dayside dynamics is strongly controlled by the interaction between the Interplanetary Magnetic Field (IMF) and the Earth's magnetic field near the dayside magnetopause, while nightside ionospheric dynamics ... -
Transient high latitude geomagnetic response to rapid increases in solar wind dynamic pressure
Madelaire, Michael; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Ohma, Anders (Journal article; Peer reviewed, 2022-08-16)Rapid changes in solar wind dynamic pressure can produce a transient geomagnetic response in the high latitude ionosphere. In this study we carry out a superposed epoch analysis of the geomagnetic response based on 2,058 ...