• Collisionless Magnetic Reconnection in an Asymmetric Oxygen Density Configuration 

      Kolstø, Håkon Midthun; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Tenfjord, Paul; Spinnangr, Susanne Flø; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2020)
      Combined with the magnetic field, the distribution of charged particles in the inflow region is expected to control the rate of magnetic reconnection. This paper investigates how the reconnection process is altered by a ...
    • The Cusp as a VLF Saucer Source: First Rocket Observations of Long‐Duration VLF Saucers on the Dayside 

      Moser, Chrystal; LaBelle, James William; Hatch, Spencer Mark; Moen, Jøran Idar; Spicher, Andres; Takahashi, Toru; Kletzing, Craig A.; Bounds, Scott Randolph; Oksavik, Kjellmar; Sigernes, Fred; Yeoman, Timothy K. (Journal article; Peer reviewed, 2021)
      Auroral whistler‐mode radio emissions called saucers are of fundamental interest because they require an unusually stationary emission process in the dynamic auroral environment, and it is a mystery how that can happen in ...
    • Dayside Field-Aligned Current Impacts on Ionospheric Irregularities 

      Follestad, Anna Kristine Fæhn; Herlingshaw, Katie; Ghadjari, Hossein; Knudsen, David J.; McWilliams, Kathryn A.; Moen, Jøran Idar; Spicher, Andres; Wu, Jingjing; Oksavik, Kjellmar (Journal article; Peer reviewed, 2020)
      Global Navigation Satellite Systems (GNSS) are subject to disturbances caused by plasma irregularities in the ionosphere. Studies have suggested that in addition to the gradient drift and Kelvin‐Helmholtz instabilities, ...
    • Dependence of Sudden Stratospheric Warmings on Internal and External Drivers 

      Salminen, Antti; Asikainen, T.; Maliniemi, Ville Aleksi; Mursula, K. (Journal article; Peer reviewed, 2020)
      A sudden stratospheric warming (SSW) is a large-scale disturbance of the wintertime stratosphere, which occurs especially in the Northern Hemisphere. Earlier studies have shown that SSW occurrence depends on atmospheric ...
    • Directed Network of Substorms Using SuperMAG Ground‐Based Magnetometer Data 

      Orr, L; Chapman, Sandra c.; Gjerløv, Jesper (Peer reviewed; Journal article, 2019)
      We quantify the spatiotemporal evolution of the substorm ionospheric current system utilizing the SuperMAG 100+ magnetometers. We construct dynamical directed networks from this data for the first time. If the canonical ...
    • Electron inflow velocities and reconnection rates at earth's magnetopause and magnetosheath 

      Burch, James L.; Webster, James M.; Hesse, Michael; Genestreti, Kevin J.; Denton, Richard E.; Phan, Tai D.; Hasegawa, Hiroshi; Cassak, Paul A.; Torbert, Roy B.; Giles, Barbara L.; Gershman, Daniel J.; Ergun, Robert E.; Russell, Christopher T.; Strangeway, Robert J.; Le Contel, Olivier; Pritchard, Kris R.; Marshall, Andrew T.; Hwang, Kyoung-Joo; Dokgo, Kyunghwan; Fuselier, Stephen A.; Chen, Li-Jen; Wang, Shan; Swisdak, Marc; Drake, James F.; Argall, Matthew R.; Trattner, Karlheinz J.; Yamada, Masaaki; Paschmann, Götz (Journal article; Peer reviewed, 2020)
      Electron inflow and outflow velocities during magnetic reconnection at and near the dayside magnetopause are measured using satellites from NASA's Magnetospheric Multiscale (MMS) mission. A case study is examined in detail, ...
    • Estimating the Rate of Cessation of Magnetospheric Activity in AMPERE Field‐Aligned Currents 

      Moretto, T; Hesse, Michael; Vennerstrøm, Susanne; Tenfjord, Paul (Peer reviewed; Journal article, 2018-12)
      The decay of magnetospheric activity when driving is turned off (to a minimum) was measured in total field‐aligned current estimates from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) ...
    • An explicit IMF By dependence on solar wind ‐ magnetosphere coupling 

      Reistad, Jone Peter; Laundal, Karl Magnus; Ohma, Anders; Moretto, Therese; Milan, Steve (Peer reviewed; Journal article, 2019)
      Presently, all empirical coupling functions quantifying the solar wind—magnetosphere energy—or magnetic flux conversion assume that the coupling is independent of the sign of the dawn-dusk component (B𝑦) of the Interplanetary ...
    • The Impact of Oxygen on the Reconnection Rate 

      Tenfjord, Paul; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Spinnangr, Susanne Flø; Kolstø, Håkon Midthun (Peer reviewed; Journal article, 2019-05-29)
      We investigate the role of a background oxygen population in magnetic reconnection, using particle‐in‐cell simulations. We run several simulations, with different initial oxygen temperatures and densities, to understand ...
    • Ion Behaviors in the Reconnection Diffusion Region of a Corrugated Magnetotail Current Sheet 

      Wang, Shan; Chen, Li-Jen; Bessho, Naoki; Hesse, Michael; Giles, Barbara L; Moore, Thomas E (Journal article; Peer reviewed, 2019)
      The current sheet structure and ion behaviors in a magnetotail reconnection diffusion region are investigated. The multispacecraft analysis suggests a corrugated current sheet structure, interpreted as due to a flapping ...
    • Magnetic Effects of Plasma Pressure Gradients in the Upper F Region 

      Laundal, Karl Magnus; Hatch, Spencer Mark; Moretto, Therese (Peer reviewed; Journal article, 2019)
      The Swarm satellites fly at altitudes that at polar latitudes are generally assumed to only contain currents that are aligned with the local magnetic field. Therefore, disturbances along the main field direction are mainly ...
    • Magnetic Reconnection in a Quasi-Parallel Shock: Two-Dimensional Local Particle-in-Cell Simulation 

      Bessho, Naoki; Chen, Lijen; Wang, Shan; Hesse, Michael; Wilson, Lynn B. (Peer reviewed; Journal article, 2019)
      Magnetic reconnection in a quasi‐parallel bow shock is investigated with two‐dimensional local particle‐in‐cell simulations. In the shock transition and downstream regions, large amplitude magnetic fluctuations exist, and ...
    • Magnetospheric Multiscale Observations of an Expanding Oxygen Wave in Magnetic Reconnection 

      Kolstø, Håkon Midthun; Norgren, Astrid Elisabet Cecilia; Hesse, Michael; Chen, Li-Jen; Tenfjord, Paul; Spinnangr, Susanne Flø; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2021)
      Heavier plasma species such as oxygen ions can have a large impact on the magnetic reconnection process. It has been hypothesized that the acceleration of demagnetized oxygen ions by the Hall electric field will lead to ...
    • Mass‐loading the Earth's dayside magnetopause boundary layer and its effect on magnetic reconnection 

      Fuselier, Stephen; Trattner, K.J.; Petrinec, Steve M.; Denton, Mike; Toledo, Sergio P.A.; Andrè, M.; Aunai, N; Chappell, Charles Richard; Glocer, Alex; Haaland, Stein; Hesse, Michael; Kistler, Lynn M.; Li, Wenya; Moore, T. E.; Graham, Daniel B.; Alm, Love; Tenfjord, Paul; Dargen, Jeremy; Vines, Sarah; Nykyri, K.; Burch, James L; Strangeway, Robert J. (Peer reviewed; Journal article, 2019)
      When the interplanetary magnetic field is northward for a period of time, O+ from the high‐latitude ionosphere escapes along reconnected magnetic field lines into the dayside magnetopause boundary layer. Dual‐lobe reconnection ...
    • MMS Measurements of the Vlasov Equation: Probing the Electron Pressure Divergence Within Thin Current Sheets 

      Shuster, JR; Gershman, Daniel J; Chen, LJ; Wang, S; Bessho, Naoki; Dorelli, John C; da Silva, DE; Giles, Barbara L; Paterson, William R.; Denton, Richard E; Schwartz, S. J.; Norgren, Astrid Elisabet Cecilia; Wilder, F.D.; Cassak, P.A.; Swisdak, M; Uritsky, Vadim; Schiff, C.; Rager, AC; Smith, S; Avanov, LA; Vinas, AF (Journal article; Peer reviewed, 2019)
      We investigate the kinetic structure of electron‐scale current sheets found in the vicinity of the magnetopause and embedded in the magnetosheath within the reconnection exhaust. A new technique for computing terms of the ...
    • MMS Observations of Multiscale Hall Physics in the Magnetotail 

      Alm, Love; André, Mats; Graham, Daniel B.; Khotyaintsev, Yuri V.; Vaivads, Andris; Chappell, Charles Richard; Dargent, Jérémy; Fuselier, Stephen A.; Haaland, Stein; Lavraud, Benoit; Li, Wenya; Tenfjord, Paul; Toledo-Redondo, Sergio; Vines, Sarah K. (Journal article; Peer reviewed, 2019)
      We present Magnetospheric Multiscale mission (MMS) observations of Hall physics in the magnetotail, which compared to dayside Hall physics is a relatively unexplored topic. The plasma consists of electrons, moderately cold ...
    • Observational evidence for throat aurora being associated with magnetopause reconnection 

      Han, De-Sheng; Xu, Tong; Jin, Yaqi; Oksavik, Kjellmar; Chen, Xiangcai; Liu, Jian-Jun; Zhang, Qinghe; Baddeley, Lisa; Herlingshaw, Katie (Peer reviewed; Journal article, 2019)
      Throat auroras have been suggested to be related to indentations on the subsolar magnetopause. However, the indentation generation process and the resulting ionospheric responses have remained unknown. An EISCAT Svalbard ...
    • Observational Evidence of Magnetic Reconnection in the Terrestrial Bow Shock Transition Region 

      Wang, Shan; Chen, Li-Jen; Bessho, Naoki; Hesse, Michael; Wilson, Lynn B.; Giles, Barbara; Moore, Thomas E.; Russell, Christopher T.; Torbert, Roy B.; Burch, James L. (Journal article; Peer reviewed, 2019)
      We report evidence of magnetic reconnection in the transition region of the Earth's bow shock when the angle between the shock normal and the immediate upstream magnetic field is 65°. An ion‐skin‐depth‐scale current sheet ...
    • On the Impact of a Streaming Oxygen Population on Collisionless Magnetic Reconnection 

      Kolstø, Håkon Midthun; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Tenfjord, Paul; Spinnangr, Susanne Flø; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2020)
      Using 2.5-D Particle-In-Cell (PIC) simulations, we investigate how magnetotail reconnection is affected by a cold, streaming, oxygen plasma population, attributed to an ionospheric source, in the inflow region. As the ...
    • Overview of the Rocket Experiment for NeutralUpwelling Sounding Rocket 2 (RENU2) 

      Lessard, Marc R.; Fritz, Bruce; Sadler, Brent; Cohen, Ian J.; Kenward, David; Godbole, Niharika; Clemmons, James H.; Hecht, James H.; Lynch, Kristina A.; Harrington, Meghan; Roberts, Thomas M.; Hysell, David; Crowley, Geoff; Sigernes, Fred; Syrjäsuo, Mikko; Ellingsen, Pål Gunnar; Partamies, Noora; Moen, Jøran Idar; Clausen, Lasse Boy Novock; Oksavik, Kjellmar; Yeoman, Timothy (Journal article; Peer reviewed, 2020)
      The Rocket Experiment for Neutral Upwelling 2 (RENU2) rocket was launched on 13 December 2015 at 07:34 UT. The payload transited the cusp region during a neutral upwelling event, supported by a comprehensive set of onboard ...