Browsing Bergen Open Research Archive by Author "Tenfjord, Paul Arne Riksheim"

Now showing items 1-11 of 11

    • Asymmetrically Varying Guide Field During Magnetic Reconnection: Particle-In-Cell Simulations 

      Spinnangr, Susanne Flø; Tenfjord, Paul Arne Riksheim; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Kolstø, Håkon Midthun; Kwagala, Norah Kaggwa; Jørgensen, Therese; Jimenez, Judit Perez-Coll (Journal article; Peer reviewed, 2022)
      Using fully kinetic particle-in-cell modeling, we investigate how magnetic reconnection responds to a varying guide field in one of the inflow regions. We find that the reconnection rate varies significantly when the ...

    • Electron Behavior Around the Onset of Magnetic Reconnection 

      Spinnangr, Susanne Flø; Hesse, Michael; Tenfjord, Paul Arne Riksheim; Norgren, Cecilia; Kolstø, Håkon Midthun; Kwagala, Norah Kaggwa; Jørgensen, Therese; Phan, Tai D. (Journal article; Peer reviewed, 2022)
      We investigate the onset of magnetic reconnection, utilizing a fully kinetic Particle-In-Cell (PIC) simulation. Characteristic features of the electron phase-space distributions immediately before reconnection onset are ...

    • Evolution of IMF By Induced Asymmetries: The Role of Tail Reconnection 

      Ohma, Anders; Østgaard, Nikolai; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Tenfjord, Paul Arne Riksheim (Journal article; Peer reviewed, 2021)
      North-south asymmetries arise in the magnetosphere-ionosphere system when a significant east-west (By) component is present in the interplanetary magnetic field (IMF). During such conditions, a By component with the same ...

    • How the Ionosphere Responds Dynamically to Magnetospheric Forcing 

      Laundal, Karl Magnus; Hatch, Spencer Mark; Reistad, Jone Peter; Ohma, Anders; Tenfjord, Paul Arne Riksheim; Madelaire, Michael (Journal article; Peer reviewed, 2024)
      Ground magnetic field variations have been used to investigate ionospheric dynamics for more than a century. They are usually explained in terms of an electric circuit in the ionosphere driven by an electric field, but ...

    • Impacts of Ionospheric Ions on Magnetic Reconnection and Earth's Magnetosphere Dynamics 

      Toledo-Redondo, S; Andre, M; Aunai, N; Chappell, Charles Richard; Dargent, Jeremy; Fuselier, S.; Glocer, Alex; Graham, D. B.; Håland, Stein Egil; Hesse, M.; Kistler, L. M.; Lavraud, B.; Li, W.; Moore, T. E.; Tenfjord, Paul Arne Riksheim; Vines, S. K. (Journal article; Peer reviewed, 2021)
      Ionospheric ions (mainly H+, He+, and O+) escape from the ionosphere and populate the Earth's magnetosphere. Their thermal energies are usually low when they first escape the ionosphere, typically a few electron volt to ...

    • 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 ...

    • The Micro-Macro Coupling of Mass-Loading in Symmetric Magnetic Reconnection With Cold Ions 

      Spinnangr, Susanne Flø; Hesse, Michael; Tenfjord, Paul Arne Riksheim; Norgren, Astrid Elisabet Cecilia; Kolstø, Håkon Midthun; Kwagala, Norah Kaggwa; Jørgensen, Therese Moretto (Journal article; Peer reviewed, 2021)
      We investigate how magnetic reconnection is influenced by an inflow of a dense cold ion population. We compare two 2.5D Particle-In-Cell simulations, one containing the cold population and one without. We find that the ...

    • Millisecond observations of nonlinear wave–electron interaction in electron phase space holes 

      Norgren, Astrid Elisabet Cecilia; Graham, Daniel B.; Argall, Matthew; Steinvall, Konrad; Hesse, Michael; Khotyaintsev, Yuri V.; Vaivads, Andris; Tenfjord, Paul Arne Riksheim; Gershman, Daniel J; Lindqvist, Per-Arne; Burch, James L; Plaschke, Ferdinand (Journal article; Peer reviewed, 2022)
      Electron phase space holes (EHs) associated with electron trapping are commonly observed as bipolar electric field signatures in both space and laboratory plasma. Until recently, it has not been possible to resolve EHs in ...

    • On the Presence and Thermalization of Cold Ions in the Exhaust of Antiparallel Symmetric Reconnection 

      Norgren, Astrid Elisabet Cecilia; Tenfjord, Paul Arne Riksheim; Hesse, Michael; Toledo-Redondo, Sergio; Li, Wenya; Xu, Yin; Kwagala, Norah Kaggwa; Spinnangr, Susanne Flø; Kolstø, Håkon Midthun; Moretto, Therese (Journal article; Peer reviewed, 2021)
      Using fully kinetic 2.5 dimensional particle-in-cell simulations of anti-parallel symmetric magnetic reconnection, we investigate how initially cold ions are captured by the reconnection process, and how they evolve and ...

    • 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) ...

    • The Role of Resistivity on the Efficiency of Magnetic Reconnection in MHD 

      Jimenez, Judit Perez-Coll; Tenfjord, Paul Arne Riksheim; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Kwagala, Norah Kaggwa; Kolstø, Håkon Midthun; Spinnangr, Susanne Flø (Journal article; Peer reviewed, 2022)
      Using a resistive MagnetoHydroDynamic (MHD) simulation, we study how the magnitude and shape of diffusion influence magnetic reconnection. Specifically, we investigate how and why the reconnection rate is influenced by ...