Blar i Bergen Open Research Archive på forfatter "Vanhamäki, H."
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Effect of ICME-Driven Storms on Field-Aligned and Ionospheric Currents From AMPERE and SuperMAG
Pedersen, M.N.; Vanhamäki, H.; Aikio, A.T.; Waters, C.L.; Gjerløv, Jesper; Käki, S.; Workayehu, A.B. (Journal article; Peer reviewed, 2022)This study investigates the field-aligned currents (FACs) and ionospheric equivalent currents for interplanetary coronal mass ejection (ICME)-driven storms by considering 45 events with a minimum Dst ≤ −50 nT. The FACs and ... -
Electrojet Estimates From Mesospheric Magnetic Field Measurements
Laundal, Karl Magnus; Yee, J.H.; Merkin, V.G.; Gjerløv, Jesper; Vanhamäki, H.; Reistad, Jone Peter; Madelaire, Michael; Sorathia, K.; Espy, Patrick Joseph (Journal article; Peer reviewed, 2021)The auroral electrojet is traditionally measured remotely with magnetometers on ground or in low Earth orbit (LEO). The sparse distribution of measurements, combined with a vertical distance of some 100 km to ground and ... -
Field-Aligned and Ionospheric Currents by AMPERE and SuperMAG During HSS/SIR-Driven Storms
Pedersen, M.N.; Vanhamäki, H.; Aikio, A.T.; Käki, S.; Workayehu, A.B.; Waters, C.L.; Gjerløv, Jesper (Journal article; Peer reviewed, 2021)This study considers 28 geomagnetic storms with Dst $\leq-50$ nT driven by high-speed streams (HSSs) and associated stream interaction regions (SIRs) during 2010-2017. Their impact on ionospheric horizontal and field-aligned ... -
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 ...