Blar i Department of Physics and Technology på tidsskrift "Frontiers in Astronomy and Space Sciences"

Viser treff 1-15 av 15

    • Bifurcated Current Sheet Observed on the Boundary of Kelvin-Helmholtz Vortices 

      Hwang, K.-J.; Dokgo, K.; Choi, E.; Burch, J.L.; Sibeck, D.G.; Giles, B.L.; Norgren, Astrid Elisabet Cecilia; Nakamura, T.K.M.; Graham, D.B.; Khotyaintsev, Y.; Shi, Q.Q.; Gershman, D.J.; Pollock, C.J.; Ergun, R.E.; Torbert, R.B.; Russell, C.T.; Strangeway, R.J. (Journal article; Peer reviewed, 2021)
      On May 5, 2017 MMS observed a bifurcated current sheet at the boundary of Kelvin-Helmholtz vortices (KHVs) developed on the dawnside tailward magnetopause. We use the event to enhance our understanding of the formation and ...

    • Cluster and MMS simultaneous observations of magnetosheath high speed jets and their impact on the magnetopause 

      Escoubet, C. P.; Hwang, KJ; Toledo-Redondo, Sergio; Turc, Lucile; Haaland, Stein; Aunai, N; Dargent, Jeremy; Eastwood, Jonathan P.; Fear, Robert C.; Fu, H.; Genestreti, Kevin; Graham, Daniel B.; Khotyaintsev, Yuri V.; Lapenta, G.; Lavraud, Benoit; Norgren, Cecilia; Sibeck, David G.; Varsani, Ali; Berchem, J.; Dimmock, A (Journal article; Peer reviewed, 2020-01-31)
      When the supersonic solar wind encounters the Earth's magnetosphere a shock, called bow shock, is formed and the plasma is decelerated and thermalized in the magnetosheath downstream from the shock. Sometimes, however, due ...

    • Dependence of the global dayside reconnection rate on interplanetary magnetic field By and the earth’s dipole tilt 

      Reistad, Jone Peter; Holappa, Lauri; Ohma, Anders; Gabrielse, Christine; Sur, Dibyendu; Asikainen, Timo; DeJong, Anna (Journal article; Peer reviewed, 2022)
      In the recent years, significant attention has been given to the combined effect of Interplanetary Magnetic Field (IMF) duskward component (By) and dipole tilt on the global magnetosphere-ionosphere system response. Numerous ...

    • Evolution of IMF By induced asymmetries during substorms: Superposed epoch analysis at geosynchronous orbit 

      Ohma, Anders; Laundal, Karl Magnus; Reistad, Jone Peter; Østgaard, Nikolai (Journal article; Peer reviewed, 2022)
      The By component of the magnetic field inside the magnetosphere is positively correlated with the By component of the Interplanetary Magnetic Field (IMF). This leads to asymmetries in aurora, plasma convection and electric ...

    • Geomagnetic Response to Rapid Increases in Solar Wind Dynamic Pressure: Event Detection and Large Scale Response 

      Madelaire, Michael; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Ohma, Anders; Haaland, Stein Egil (Journal article; Peer reviewed, 2022)
      Discontinuities in the solar wind trigger a variety of processes in the magnetosphere-ionosphere system. A rapid increase in solar wind dynamic pressure causes compression of the magnetosphere. This manifests itself as a ...

    • Interhemispheric asymmetries of neutral upwelling and ion upflow 

      Lessard, Marc R.; Damsell, Alec; Sadler, F. Brent; Oksavik, Kjellmar; Clausen, Lasse (Journal article; Peer reviewed, 2023)
      This work addresses interhemispheric differences in cusp-related neutral density enhancements. The focus is on enhancements that are driven by Poleward Moving Auroral Forms (PMAF), which provide a repetitive sequence of ...

    • The Lompe code: A Python toolbox for ionospheric data analysis 

      Hovland, Amalie Øie; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Walker, Simon; Madelaire, Michael; Ohma, Anders (Journal article; Peer reviewed, 2022)
      A recent paper by Laundal et al. (2022c) presented a new technique to combine all available measurements of polar ionospheric electrodynamics; magnetic field measurements from ground and space, ionospheric convection data ...

    • 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 ...

    • The Predictive Capabilities of the Auroral Electrojet Index for Medium Energy Electron Precipitation 

      Tyssøy, Hilde Nesse; Partamies, Noora; Babu, Eldho Midhun; Smith-Johnsen, Christine; Salice, Josephine Alessandra (Journal article; Peer reviewed, 2021)
      The chemical imprint of the energetic electron precipitation on the atmosphere is now acknowledged as a part of the natural forcing of the climate system. It has, however, been questioned to which degree current proxies ...

    • Quantification of Cold-Ion Beams in a Magnetic Reconnection Jet 

      Li, Yu-Xuan; Li, Wen-Ya; Tang, Bin-Bin; Norgren, C.; He, Jian-Sen; Wang, Chi; Zong, Qiu-Gang; Toledo-Redondo, S.; André, M.; Chappell, C.; Dargent, J.; Fuselier, S.A.; Glocer, A.; Graham, D.B.; Haaland, S.; Kistler, L.; Lavraud, B.; Moore, T.E.; Tenfjord, P.; Vines, S.K.; Burch, J. (Journal article; Peer reviewed, 2021)
      Cold (few eV) ions of ionospheric origin are widely observed in the lobe region of Earth’s magnetotail and can enter the ion jet region after magnetic reconnection is triggered in the magnetotail. Here, we investigate a ...

    • 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 ...

    • Statistical Analysis of Bifurcating Region 2 Field-Aligned Currents Using AMPERE 

      Sangha, H.K.; Milan, Stephen Eric; Anderson, B.J.; Korth, H. (Journal article; Peer reviewed, 2022)
      We present a statistical analysis of the occurrence of bifurcations of the Region 2 (R2) Field-Aligned Current (FAC) region, observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). ...

    • Testing the mirror symmetry of Birkeland and ionospheric currents with respect to magnetic latitude, dipole tilt angle, and IMF By 

      Hatch, Spencer Mark; Laundal, Karl Magnus; Reistad, Jone Peter (Journal article; Peer reviewed, 2022)
      It is often assumed that on average, polar ionospheric electrodynamics in the Northern and Southern Hemispheres are mirror symmetric or antisymmetric with respect to the interplanetary magnetic field By component and the ...

    • Transient high latitude geomagnetic response to rapid increases in solar wind dynamic pressure 

      Madelaire, Michael; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark; Ohma, Anders (Journal article; Peer reviewed, 2022-08-16)
      Rapid changes in solar wind dynamic pressure can produce a transient geomagnetic response in the high latitude ionosphere. In this study we carry out a superposed epoch analysis of the geomagnetic response based on 2,058 ...

    • Using machine learning to characterize solar wind driving of convection in the terrestrial magnetotail lobes 

      Cao, Xin; Halekas, Jasper; Haaland, Stein Egil; Ruhunusiri, Suranga; Glassmeier, Karl-Heinz (Journal article; Peer reviewed, 2023)
      In order to quantitatively investigate the mechanism of how magnetospheric convection is driven in the region of magnetotail lobes on a global scale, we analyzed data from the ARTEMIS spacecraft in the deep tail and data ...