Now showing items 1-20 of 32

  • 3D MHD modeling of twisted coronal loops 

    Reale, F.; Orlando, S.; Guarrasi, M.; Mignone, A.; Peres, G.; Hood, A. W.; Priest, E. R. (2016-10-10) - Journal article
    We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated ...
  • Bombs and flares at the surface and lower atmosphere of the Sun 

    Hansteen, V. H.; Archontis, V.; Pereira, T. M. D.; Carlsson, M.; Rouppe van der Voort, L.; Leenaarts, J. (2017-04-10) - Journal article
    A spectacular manifestation of solar activity is the appearance of transient brightenings in the far wings of the Hα line, known as Ellerman bombs (EBs). Recent observations obtained by the Interface Region Imaging ...
  • Clusters of small eruptive flares produced by magnetic reconnection in the Sun 

    Archontis, V.; Hansteen, V. (2014-06-10) - Journal article
    We report on the formation of small solar flares produced by patchy magnetic reconnection between interacting magnetic loops. A three-dimensional (3D) magnetohydrodynamic (MHD) numerical experiment was performed, where a ...
  • A complex solar coronal jet with two phases 

    Chen, Jie; Su, Jiangtao; Deng, Yuanyong; Priest, E. R. (2017-05-04) - Journal article
    Jets often occur repeatedly from almost the same location. In this paper, a complex solar jet was observed with two phases to the west of NOAA AR 11513 on 2012 July 2. If it had been observed at only moderate resolution, ...
  • Dynamic properties of bright points in an active region 

    Keys, P.H.; Mathioudakis, M.; Jess, D.B.; MacKay, D.H.; Keenan, F.P. (2014-06-20) - Journal article
    Context. Bright points (BPs) are small-scale, magnetic features ubiquitous across the solar surface. Previously, we have observed and noted their properties for quiet Sun regions. Here, we determine the dynamic properties ...
  • Elongation of flare ribbons 

    Qiu, Jiong; Longcope, Dana W.; Cassak, Paul A.; Priest, Eric R. (2017-03-20) - Journal article
    We present an analysis of the apparent elongation motion of flare ribbons along the polarity inversion line (PIL), as well as the shear of flare loops in several two-ribbon flares. Flare ribbons and loops spread along the ...
  • Emergence of non-twisted magnetic fields in the Sun : jets and atmospheric response 

    Syntelis, P.; Archontis, V.; Gontikakis, C.; Tsinganos, K. (2015-12) - Journal article
    Aims. We study the emergence of a non-twisted flux tube from the solar interior into the solar atmosphere. We investigate whether the length of the buoyant part of the flux tube (i.e. λ) affects the emergence of the field ...
  • The emergence of weakly twisted magnetic fields in the Sun 

    Archontis, Vasilis; Hood, Alan William; Tsinganos, K (2013-11-01) - Journal article
    We have studied the emergence of a weakly twisted magnetic flux tube from the upper convection zone into the solar atmosphere. It is found that the rising magnetized plasma does not undergo the classical, single Ω-shaped ...
  • The eruption of a small-scale emerging flux rope as the driver of an M-class flare and of a coronal mass ejection 

    Yan, X. L.; Jiang, C. W.; Xue, Z. K.; Wang, J. C.; Priest, E. R.; Yang, L. H.; Kong, D. F.; Cao, W. D.; Ji, H. S. (2017-08-10) - Journal article
    Solar flares and coronal mass ejections are the most powerful explosions in the Sun. They are major sources of potentially destructive space weather conditions. However, the possible causes of their initiation remain ...
  • Fine strand-like structure in the solar corona from magnetohydrodynamic transverse oscillations 

    Antolin, P.; Yokoyama, T.; Van Doorsselaere, T. (2014-05-13) - Journal article
    Current analytical and numerical modeling suggest the existence of ubiquitous thin current sheets in the corona that could explain the observed heating requirements. On the other hand, new high resolution observations of ...
  • First high-resolution spectroscopic observations of an erupting prominence within a coronal mass ejection by the Interface Region Imaging Spectrograph (IRIS) 

    Liu, Wei; De Pontieu, Bart; Vial, Jean-Claude; Title, Alan M.; Carlsson, Mats; Uitenbroek, Han; Okamoto, Takenori J.; Berger, Thomas E.; Antolin, Patrick (2015-04-21) - Journal article
    Spectroscopic observations of prominence eruptions associated with coronal mass ejections (CMEs), although relatively rare, can provide valuable plasma and three-dimensional geometry diagnostics. We report the first ...
  • Helical blowout jets in the sun : untwisting and propagation of waves 

    Lee, E.J.; Archontis, V.; Hood, A.W. (2015-01-01) - Journal article
    We report on a numerical experiment of the recurrent onset of helical "blowout" jets in an emerging flux region. We find that these jets are running with velocities of ∼100-250 km s-1 and they transfer a vast amount of ...
  • Imaging observations of magnetic reconnection in a solar eruptive flare 

    Li, Y.; Sun, X.; Ding, M. D.; Qiu, J.; Priest, E. R. (2017-01-31) - Journal article
    Solar flares are among the most energetic events in the solar atmosphere. It is widely accepted that flares are powered by magnetic reconnection in the corona. An eruptive flare is usually accompanied by a coronal mass ...
  • Impact of an L5 magnetograph on nonpotential solar global magnetic field modeling 

    Mackay, Duncan Hendry; Yeates, Anthony Robinson; Bocquet, Francois-Xavier (2016-07-12) - Journal article
    We present the first theoretical study to consider what improvement could be obtained in global non-potential modeling of the solar corona if magnetograph data were available from the L5 Lagrange point, in addition to from ...
  • Impact of flux distribution on elementary heating events 

    O'Hara, Jennifer Patricia; De Moortel, Ineke (2016-10) - Journal article
    Context. The complex magnetic field on the solar surface has been shown to contain a range of sizes and distributions of magnetic flux structures. The dynamic evolution of this magnetic carpet by photospheric flows provides ...
  • Kinematics of coronal rain in a transversely oscillating loop : ponderomotive force and rain-excited oscillations 

    Verwichte, E.; Antolin, P.; Rowlands, G.; Kohutova, P.; Neukirch, T. (2017-02) - Journal article
    Context. Coronal rain are cool dense blobs that form in solar coronal loops and are a manifestation of catastrophic cooling linked to thermal instability. Once formed, rain falls towards the solar surface at sub-ballistic ...
  • Loss cone evolution and particle escape in collapsing magnetic trap models in solar flares 

    Eradat Oskoui, Solmaz; Neukirch, Thomas; Grady, Keith James (2014-03) - Journal article
    Context. Collapsing magnetic traps (CMTs) have been suggested as one possible mechanism responsible for the acceleration of high-energy particles during solar flares. An important question regarding the CMT acceleration ...
  • An MHD avalanche in a multi-threaded coronal loop 

    Hood, Alan William; Cargill, Peter; Browning, Philippa; Tam, Kuan (2016-01-18) - Journal article
    For the first time, we demonstrate how an MHD avalanche might occur in a multi-threaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs ...
  • Modeling observed decay-less oscillations as resonantly enhanced Kelvin-Helmholtz vortices from transverse MHD waves and their seismological application 

    Antolin, P.; De Moortel, Ineke; Van Doorsselaere, T.; Yokoyama, T. (2016-10-12) - Journal item
    In the highly structured solar corona, resonant absorption is an unavoidable mechanism of energy transfer from global transverse MHD waves to local azimuthal Alfvén waves. Due to its localised nature, a direct detection ...
  • Modeling the dispersal of an active region : quantifying energy input into the corona 

    Mackay, Duncan Hendry; Green, Lucie; van Ballegooijen, Aad (2011-03-10) - Journal article
    In this paper, a new technique for modeling nonlinear force-free fields directly from line-of-sight magnetogram observations is presented. The technique uses sequences of magnetograms directly as lower boundary conditions ...