• The Magnitude of IMF By Influences the Magnetotail Response to Solar Wind Forcing 

      Holappa, Lauri; Reistad, Jone Peter; Ohma, Anders; Gabrielse, Christine; Sur, Dibyendu (Journal article; Peer reviewed, 2021)
      The dynamics of substorms are known to be dominated by the North-South (Bz) component of the Interplanetary Magnetic Field (IMF), which is the most important driver of the dayside reconnection. Even though the dawn-dusk ...
    • Mechanisms responsible for asymmetric aurora between the conjugate hemispheres 

      Reistad, Jone Peter (Doctoral thesis, 2016-04)
      The work presented in this thesis is part of ongoing research within one of the research groups at the Birkeland Centre for Space Science (BCSS) at the Department of Physics and Technology, University of Bergen. Members ...
    • Modulation of Magnetospheric Substorm Frequency: Dipole Tilt and IMF By Effects 

      Ohma, Anders; Reistad, Jone Peter; Hatch, Spencer Mark (Journal article; Peer reviewed, 2021)
      Substorm activity is heavily influenced by the Interplanetary Magnetic Field (IMF) Bz component and magnetospheric substorms occur most frequently when Bz is strongly negative. The substorm occurrence rate is also affected ...
    • 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 ...
    • 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) ...
    • 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 ...
    • Quantifying the Lobe Reconnection Rate During Dominant IMF By Periods and Different Dipole Tilt Orientations 

      Reistad, Jone Peter; Laundal, Karl Magnus; Østgaard, Nikolai; Ohma, Anders; Burrell, Angeline G.; Hatch, Spencer Mark; Håland, Stein Egil; Thomas, Evan G. (Journal article; Peer reviewed, 2021)
      Lobe reconnection is usually thought to play an important role in geospace dynamics only when the Interplanetary Magnetic Field (IMF) is mainly northward. This is because the most common and unambiguous signature of lobe ...
    • The relationship between interhemispheric asymmetries in polar ionospheric convection and the magnetic field line footpoint displacement field 

      Laundal, Karl Magnus; Madelaire, Michael; Ohma, Anders; Reistad, Jone Peter; Hatch, Spencer Mark (Journal article; Peer reviewed, 2022)
      Polar electrodynamics is largely controlled by solar wind and magnetospheric forcing. Different conditions can make plasma convection and magnetic field disturbances asymmetric between hemispheres. So far, these asymmetries ...
    • The Relationship Between Large Scale Thermospheric Density Enhancements and the Spatial Distribution of Poynting Flux 

      Billett, Daniel; Clausen, Lasse Boy Novock; Archer, William; McWilliams, Kathryn A.; Håland, Stein Egil; Reistad, Jone Peter; Burchill, J. K.; Patrick, M. R.; Humberset, Beate Krøvel; Anderson, B. J.; Perry, G. W. (Journal article; Peer reviewed, 2021)
      Large thermospheric neutral density enhancements in the cusp region have been examined for many years. The Challenging Minisatellite Payload (CHAMP) satellite for example has enabled many observations of the perturbation, ...
    • Results from the intercalibration of optical low light calibration sources 2011 

      Brändström, B. Urban E.; Enell, Carl-Fredrik; Widell, Ola; Hansson, Thord; Whiter, Daniel; Mäkinen, Sanna; Mikhaylova, Daria; Axelsson, Katarina; Sigernes, Fred; Gulbrandsen, Njål; Schlatter, Nicola M.; Gjendem, Amund Gjerde; Cai, L.; Reistad, Jone Peter; Daae, Marianne; Demissie, Teferi Dejene; Andalsvik, Yngvild Linnea; Roberts, Owen; Poluyanov, Stepan Viktorovich; Chernouss, Sergey (Peer reviewed; Journal article, 2012-05-03)
      Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main ...
    • 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 Wind and Seasonal Influence on Ionospheric Currents From Swarm and CHAMP Measurements 

      Laundal, Karl Magnus; Finlay, Christopher C.; Olsen, N; Reistad, Jone Peter (Peer reviewed; Journal article, 2018-05-29)
      We present a new climatological model of the ionospheric current system, determined from magnetic measurements taken by the Challenging Minisatellite Payload (CHAMP) and Swarm satellites. The model describes the horizontal ...
    • Spatial Resolution in Inverse Problems: The EZIE Satellite Mission 

      Madelaire, Michael; Laundal, Karl Magnus; Gjerloev, J.; Hatch, Spencer Mark; Reistad, Jone Peter; Vanhamäki, H.; Waters, Colin; Ohma, Anders; Mesquita, Rafael L. A.; Merkin, Viacheslav (Journal article; Peer reviewed, 2023)
      Inverse modeling has become one of the primary methods for studying ionospheric electrodynamics, especially when using magnetic field measurements from below the ionosphere. We present a method for quantifying the spatial ...
    • Statistical Temporal Variations in the Auroral Electrojet Estimated With Ground Magnetometers in Fennoscandia 

      Walker, Simon; Laundal, Karl Magnus; Reistad, Jone Peter; Ohma, Anders; Hatch, Spencer Mark (Journal article; Peer reviewed, 2023)
      We present the implementation of an improved technique to coherently model the high-latitude ionospheric equivalent current. Using a fixed selection of 20 ground magnetometers in Fennoscandia, we present a method based on ...
    • 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 ...