Blar i Bergen Open Research Archive på forfatter "Milan, Stephen Eric"

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    • The asymmetric geospace as displayed during the geomagnetic storm on 17 August 2001 

      Østgaard, Nikolai; Reistad, Jone Peter; Tenfjord, Paul; Laundal, Karl Magnus; Rexer, Theresa; Haaland, Stein; Snekvik, Kristian; Hesse, Michael; Milan, Stephen Eric; Ohma, Anders (Peer reviewed; Journal article, 2018-11-29)
      Previous studies have shown that conjugate auroral features are displaced in the two hemispheres when the interplanetary magnetic field (IMF) has a transverse (Y) component. It has also been shown that a BY component is ...

    • Dayside and nightside magnetic field responses at 780 km altitude to dayside reconnection 

      Snekvik, Kristian; Østgaard, Nikolai; Tenfjord, Paul; Reistad, Jone Peter; Laundal, Karl Magnus; Milan, Stephen Eric; Haaland, Stein (Peer reviewed; Journal article, 2017-02)
      During southward interplanetary magnetic field, dayside reconnection will drive the Dungey cycle in the magnetosphere, which is manifested as a two‐cell convection pattern in the ionosphere. We address the response of the ...

    • Dual-Lobe Reconnection and Horse-Collar Auroras 

      Milan, Stephen Eric; Carter, Jennifer Alyson; Bower, G.E.; Imber, S.M.; Paxton, Larry J.; Anderson, Brian J.; Hairston, Marc; Hubert, Benoit (Journal article; Peer reviewed, 2020)
      We propose a mechanism for the formation of the horse-collar auroral configuration during periods of strongly northward interplanetary magnetic field (IMF), invoking the action of dual-lobe reconnection (DLR). Auroral ...

    • Influence of Off-Sun-Earth Line Distance on the Accuracy of L1 Solar Wind Monitoring 

      Milan, Stephen Eric; Carter, J.A.; Bower, G.E.; Fleetham, A.L.; Anderson, B.J. (Journal article; Peer reviewed, 2022)
      Upstream solar wind measurements from near the L1 Lagrangian point are commonly used to investigate solar wind-magnetosphere coupling. The off-Sun-Earth line distance of such solar wind monitors can be large, up to 100 RE. ...

    • Lobe Reconnection and Cusp-Aligned Auroral Arcs 

      Milan, Stephen Eric; Bower, G.E.; Carter, J.A.; Paxton, L.J.; Anderson, B.J.; Hairston, M.R. (Journal article; Peer reviewed, 2022)
      Following the St. Patrick's Day (17 March) geomagnetic storm of 2013, the interplanetary magnetic field had near-zero clock angle for almost two days. Throughout this period multiple cusp-aligned auroral arcs formed in the ...

    • Magnetospheric Flux Throughput in the Dungey Cycle: Identification of Convection State During 2010 

      Milan, Stephen Eric; Carter, Jennifer Alyson; Sangha, Harneet; Bower, G.E.; Anderson, Brian J. (Journal article; Peer reviewed, 2021)
      We quantify the contributions of different convection states to the magnetic flux throughput of the magnetosphere during 2010. To do this we provide a continuous classification of convection state for the duration of 2010 ...

    • Magnetospheric response and reconfiguration times following IMF By reversals 

      Tenfjord, Paul Arne Riksheim; Østgaard, Nikolai; Strangeway, Robert J.; Haaland, Stein; Snekvik, Kristian; Laundal, Karl Magnus; Reistad, Jone Peter; Milan, Stephen Eric (Peer reviewed; Journal article, 2017-01)
      The interaction between the interplanetary magnetic field (IMF) and the geomagnetic field at the dayside magnetopause leads to transfer of momentum and energy which changes the magnetospheric configuration, but only after ...

    • North–South Asymmetries in Earth’s Magnetic Field. Effects on High-Latitude Geospace 

      Laundal, Karl Magnus; Cnossen, Ingrid; Milan, Stephen Eric; Haaland, Stein; Coxon, John C.; Pedatella, Nick; Förster, Matthias; Reistad, Jone Peter (Peer reviewed; Journal article, 2017-03)
      The solar-wind magnetosphere interaction primarily occurs at altitudes where the dipole component of Earth’s magnetic field is dominating. The disturbances that are created in this interaction propagate along magnetic field ...

    • Observations of Asymmetric Lobe Convection for Weak and Strong Tail Activity 

      Ohma, Anders; Østgaard, Nikolai; Reistad, Jone Peter; Tenfjord, Paul; Laundal, Karl Magnus; Moretto, Therese; Haaland, Stein; Krcelic, Patrik; Milan, Stephen Eric (Journal article; Peer reviewed, 2019)
      In this study we use high‐quality convection data from the Electron Drift Instrument on board Cluster to investigate how near‐Earth tail activity affects the average convection pattern in the magnetotail lobes when the ...

    • Occurrence Statistics of Horse Collar Aurora 

      Bower, G.E.; Milan, Stephen Eric; Paxton, L.J.; Anderson, B.J. (Journal article; Peer reviewed, 2022)
      Horse collar aurora (HCA) are an auroral feature where the dawn and dusk sector auroral oval moves polewards and the polar cap becomes teardrop shaped. They form during prolonged periods of northward interplanetary magnetic ...

    • Overview of solar wind - magnetosphere - ionosphere - atmosphere coupling and the generation of magnetospheric currents 

      Milan, Stephen Eric; Clausen, Lasse Boy Novock; Coxon, John Charles; Carter, Jenny A.; Walach, Maria Theresia; Laundal, Karl Magnus; Østgaard, Nikolai; Tenfjord, Paul Arne Riksheim; Reistad, Jone Peter; Snekvik, Kristian; Korth, Haje; Anderson, Brian J. (Peer reviewed; Journal article, 2017-03)
      We review the morphology and dynamics of the electrical current systems of the terrestrial magnetosphere and ionosphere. Observations from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) ...

    • Separation and quantification of ionospheric convection sources: 1. A new technique 

      Reistad, Jone Peter; Laundal, Karl Magnus; Østgaard, Nikolai; Ohma, Anders; Haaland, Stein; Oksavik, Kjellmar; Milan, Stephen Eric (Peer reviewed; Journal article, 2019-07-04)
      This paper describes a novel technique that allows separation and quantification of different sources of convection in the high‐latitude ionosphere. To represent the ionospheric convection electric field, we use the Spherical ...

    • Separation and quantification of ionospheric convection sources: 2. The dipole tilt angle influence on reverse convection cells during northward IMF 

      Reistad, Jone Peter; Laundal, Karl Magnus; Østgaard, Nikolai; Ohma, Anders; Thomas, Evan G.; Haaland, Stein; Oksavik, Kjellmar; Milan, Stephen Eric (Peer reviewed; Journal article, 2019-07-04)
      This paper investigates the influence of Earth's dipole tilt angle on the reverse convection cells (sometimes referred to as lobe cells) in the Northern Hemisphere ionosphere during northward IMF, which we relate to ...

    • Solar Cycle and Solar Wind Dependence of the Occurrence of Large dB/dt Events at High Latitudes 

      Milan, Stephen Eric; Imber, S.M.; Fleetham, A.L.; Gjerløv, Jesper (Journal article; Peer reviewed, 2023)
      We investigate sharp changes in magnetic field that can produce Geomagnetically Induced Currents (GICs) which damage pipelines and power grids. We use one-minute cadence SuperMAG observations to find the occurrence ...

    • Statistical Analysis of Bifurcating Region 2 Field-Aligned Currents Using AMPERE 

      Sangha, H.K.; Milan, Stephen Eric; Anderson, B.J.; Korth, H. (Journal article; Peer reviewed, 2022)
      We present a statistical analysis of the occurrence of bifurcations of the Region 2 (R2) Field-Aligned Current (FAC) region, observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). ...

    • Substorm Onset Latitude and the Steadiness of Magnetospheric Convection 

      Milan, Stephen Eric; Walach, Maria Theresia; Carter, JA; Sangha, Harneet; Anderson, Brian J. (Peer reviewed; Journal article, 2019-03-10)
      We study the role of substorms and steady magnetospheric convection (SMC) in magnetic flux transport in the magnetosphere, using observations of field‐aligned currents by the Active Magnetosphere and Planetary Electrodynamics ...