Blar i Department of Physics and Technology på tidsskrift "Geophysical Research Letters"

Viser treff 21-38 av 38

    • 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 ...

    • 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 ...

    • 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 ...

    • Multi-Pulse Corona Discharges in Thunderclouds Observed in Optical and Radio Bands 

      Li, Dongshuai; Luque, Alejandro; Lehtinen, Nikolai Grigorievich; Gordillo-Vázquez, F.J.; Neubert, Torsten; Lu, Gaopeng; Chanrion, Olivier; Zhang, Hongbo; Østgaard, Nikolai; Reglero, Víctor (Journal article; Peer reviewed, 2022)
      How lightning initiates inside thunderclouds remains a major puzzle of atmospheric electricity. By monitoring optical emissions from thunderstorms, the Atmosphere-Space Interactions Monitor (ASIM) onboard the International ...

    • 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 ...

    • Observations of Blue Corona Discharges in Thunderclouds 

      Husbjerg, Lasse Skaaning; Neubert, Torsten; Chanrion, Olivier; Dimitriadou, Krystallia; Li, Dongshuai; Stendel, Martin; Kaas, Eigil; Østgaard, Nikolai; Reglero, Victor (Journal article; Peer reviewed, 2022)
      Blue electric streamer discharges in the upper reaches of thunderclouds are observed as flashes of 337.0 nm (blue) with faint or no emissions of 777.4 nm (red). Analyzing 3 years of measurements by the Atmosphere-Space ...

    • 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 ...

    • Possible Ionospheric Influence on Substorm Onset Location 

      Elhawary, Reham Zakaria Ahmed Mohamed; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark (Journal article; Peer reviewed, 2022)
      Auroral substorm onset locations are highly unpredictable. Previous studies have shown that the By component of the interplanetary magnetic field (IMF) explains ∼5% of the variation in onset magnetic local time (MLT), while ...

    • The Quasi-Linear Absolute Angular Momentum Slope of Tropical Cyclones Under Rapid Intensification 

      Tao, Dandan; Nystrom, Robert; Bell, Michael (Journal article; Peer reviewed, 2023)
      Tropical cyclone (TC) low-level tangential wind structure is known to be an important input for risk assessment (e.g., storm surge). However, a realistic TC wind structure model with easy implementation is still needed for ...

    • Spectral Observations of Optical Emissions Associated With Terrestrial Gamma-Ray Flashes 

      Heumesser, Matthias; Chanrion, Olivier; Neubert, Torsten; Christian, Hugh J.; Dimitriadou, Krystallia; Gordillo-Vazquez, Francisco J.; Luque, Alejandro; Pérez-Invernón, F. J.; Blakeslee, Richard J.; Østgaard, Nikolai; Reglero, Victor; Köhn, Christoph (Journal article; Peer reviewed, 2021)
      The Atmosphere-Space Interactions Monitor measures Terrestrial Gamma-Ray Flashes (TGFs) simultaneously with optical emissions from associated lightning activity. We analyzed optical measurements at 180–230, 337, and 777.4 ...

    • 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 ...

    • Transition in Optical and Radio Features During the Early Development of Negative Intracloud Leader 

      Huang, Anjing; Cummer, Steven A.; Pu, Yunjiao; Chanrion, Olivier A.; Neubert, Torsten; Reglero, Victor; Østgaard, Nikolai (Journal article; Peer reviewed, 2022)
      What happens when the upward in-cloud (IC) breakdown transitions into horizontally expanding extension? Optical observations of this transition in IC lightning have not previously been reported. We identify the radio and ...

    • Will Climate Change Impact Polar NOx Produced by Energetic Particle Precipitation? 

      Maliniemi, Ville Aleksi; Marsh, Daniel R.; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine (Journal article; Peer reviewed, 2020)
      Energetic electron precipitation (EEP) is an important source of polar nitrogen oxides (NOx) in the upper atmosphere. During winter, mesospheric NOx has a long chemical lifetime and is transported to the stratosphere by ...