Now showing items 21-32 of 32

    • 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 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 ...
    • North-south asymmetries in cold plasma density in the magnetotail lobes: Cluster observations 

      Haaland, Stein; Lybekk, Bjørn; Maes, Lukas; Laundal, Karl Magnus; Pedersen, Amund; Tenfjord, Paul; Ohma, Anders; Østgaard, Nikolai; Reistad, Jone Peter; Snekvik, Kristian (Peer reviewed; Journal article, 2017-01)
      In this paper, we present observations of cold (0–70 eV) plasma density in the magnetotail lobes. The observations and results are based on 16 years of Cluster observation of spacecraft potential measurements converted ...
    • 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 ...
    • Observations of asymmetries in ionospheric return flow during different levels of geomagnetic activity 

      Reistad, Jone Peter; Østgaard, Nikolai; Laundal, Karl Magnus; Ohma, Anders; Snekvik, Kristian; Tenfjord, Paul; Grocott, Adrian; Oksavik, Kjellmar; Milan, Steve; Haaland, Stein (Peer reviewed; Journal article, 2018-06)
      It is known that the magnetic field of the Earth's closed magnetosphere can be highly displaced from the quiet‐day configuration when interacting with the interplanetary magnetic field (IMF), an asymmetry largely controlled ...
    • The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field 

      Li, Kun; Förster, Matthias; Rong, Zhaojin; Haaland, Stein; Kronberg, E.; Cui, Jun; Chai, Lihui; Wei, Yong (Journal article; Peer reviewed, 2020)
      When the geomagnetic field is weak, the small mirror force allows precipitating charged particles to deposit energy in the ionosphere. This leads to an increase in ionospheric outflow from the Earth's polar cap region, but ...
    • Seasonal and hemispheric asymmetries of F‐region polar cap plasma density: Swarm and CHAMP observations 

      Hatch, Spencer Mark; Haaland, Stein; Laundal, Karl Magnus; Moretto, Therese; Yau, Andrew; Bjoland, Lindis Merete; Reistad, Jone Peter; Ohma, Anders; Oksavik, Kjellmar (Journal article; Peer reviewed, 2020)
      One of the primary mechanisms of loss of Earth's atmosphere is the persistent “cold” ( urn:x-wiley:jgra:media:jgra56068:jgra56068-math-0001 20 eV) ion outflow that has been observed in the magnetospheric lobes over large ...
    • 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 illumination control of ionospheric outflow above polar cap arcs 

      Maes, Lukas; Maggiolo, Romain; De Keyser, Johan; Dandouras, Iannis; Fear, Robert C.; Fontaine, Dominique; Haaland, Stein (Peer reviewed; Journal article, 2015-03-12)
      We measure the flux density, composition, and energy of outflowing ions above the polar cap, accelerated by quasi-static electric fields parallel to the magnetic field and associated with polar cap arcs, using Cluster. ...
    • Suprathermal Fe in the Earth's Plasma Environment: Cluster RAPID Observations 

      Haaland, Stein; Daly, Patrick W.; Vilenius, Esa; Krcelic, Patrik; Dandouras, Iannis (Journal article; Peer reviewed, 2020)
      Baryonic matter in geospace is almost exclusively in a plasma state, with protons (H +) and to some extent ionized helium (He) and oxygen (O) being the dominant ion species. But also other heavier ion species and even ...