Now showing items 1-20 of 47

  • Alfven wave phase-mixing and damping in the ion cyclotron range of frequencies 

    Threlfall, J.; McClements, K. G.; De Moortel, I. (2011-01) - Journal article
    Aims. We determine the effect of the Hall term in the generalised Ohm's law on the damping and phase mixing of Alfven waves in the ion cyclotron range of frequencies in uniform and non-uniform equilibrium plasmas. Methods. ...
  • Catastrophe versus instability for the eruption of a toroidal solar magnetic flux rope 

    Kliem, B.; Lin, J.; Forbes, T. G.; Priest, E. R.; Toeroek, T. (2014-07-01) - Journal article
    The onset of a solar eruption is formulated here as either a magnetic catastrophe or as an instability. Both start with the same equation of force balance governing the underlying equilibria. Using a toroidal flux rope in ...
  • 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 ...
  • Coronal heating and nanoflares : current sheet formation and heating 

    Bowness, Ruth; Hood, Alan William; Parnell, Clare Elizabeth (2013-12) - Journal article
    Aims: Solar photospheric footpoint motions can produce strong, localised currents in the corona. A detailed understanding of the formation process and the resulting heating is important in modelling nanoflares, as a mechanism ...
  • Coronal heating by the partial relaxation of twisted loops 

    Bareford, Michael; Hood, Alan; Browning, Philippa (2013-02) - Journal article
    Context: Relaxation theory offers a straightforward method for estimating the energy that is released when a magnetic field becomes unstable, as a result of continual convective driving. Aims: We present new results obtained ...
  • Coronal heating in multiple magnetic threads 

    Tam, Kuan Vai; Hood, Alan William; Browning, Philippa; Cargill, Peter (2015-08) - Journal article
    Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can ...
  • Damping of kink waves by mode coupling : I. Analytical treatment 

    Hood, Alan William; Ruderman, Michael; Pascoe, David James; De Moortel, Ineke; Terradas, Jaume; Wright, Andrew Nicholas (2013-03) - Journal article
    Aims. To investigate the spatial damping of propagating kink waves in an inhomogeneous plasma. In the limit of a thin tube surrounded by a thin transition layer, an analytical formulation for kink waves driven in from the ...
  • Damping of kink waves by mode coupling. II. Parametric study and seismology 

    Pascoe, David James; Hood, Alan William; De Moortel, Ineke; Wright, Andrew Nicholas (2013-02) - Journal article
    Context: Recent observations of the corona reveal ubiquitous transverse velocity perturbations that undergo strong damping as they propagate. These can be understood in terms of propagating kink waves that undergo mode ...
  • Distribution of electric currents in solar active regions 

    Török, T.; Leake, J.E.; Titov, V.S.; Archontis, V.; Mikić, Z.; Linton, M.G.; Dalmasse, K.; Aulanier, G.; Kliem, B. (2014-02-10) - Journal article
    There has been a long-standing debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region ...
  • Effect of gravitational stratification on the propagation of a CME 

    Pagano, Paolo; Mackay, Duncan Hendry; Poedts, Stefaan (2013-12-02) - Journal article
    Our aim is to study the role of gravitational stratification on the propagation of CMEs. In particular, we assess how it influences the speed and shape of CMEs and under what conditions the flux rope ejection becomes a CME ...
  • The effects of line-of-sight integration on multistrand coronal loop oscillations 

    De Moortel, Ineke; Pascoe, David James (2012-02-10) - Journal article
  • The effects of resistivity and viscosity on the Kelvin-Helmholtz instability in oscillating coronal loops 

    Howson, Thomas Alexander; De Moortel, Ineke; Antolin, Patrick (2017-03-03) - Journal article
    Aims. Investigate the effects of resistivity and viscosity on the onset and growth of the Kelvin-Helmholtz instability (KHI) in an oscillating coronal loop. Methods. We modelled a standing kink wave in a density-enhanced ...
  • 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 ...
  • Excitation and damping of broadband kink waves in the solar corona 

    Pascoe, David James; Wright, Andrew Nicholas; De Moortel, Ineke; Hood, Alan William (2015-06) - Journal article
    Context. Observations such as those by the Coronal Multi-Channel Polarimeter (CoMP) have revealed that broadband kink oscillations are ubiquitous in the solar corona. Aims. We consider footpoint-driven kink waves propagating ...
  • 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 comparison of wave observations from CoMP and AIA/SDO 

    Threlfall, James William; De Moortel, Ineke; McIntosh, Scott; Bethge, Christian (2013-08) - Journal article
    Context. Waves have long been thought to contribute to the heating of the solar corona and the generation of the solar wind. Recent observations have demonstrated evidence of quasi-periodic longitudinal disturbances and ...
  • Flux emergence and coronal eruption 

    Archontis, Vasilis; Hood, Alan William (2010-05) - Journal article
    Aims. Our aim is to study the photospheric flux distribution of a twisted flux tube that emerges from the solar interior. We also report on the eruption of a new flux rope when the emerging tube rises into a pre-existing ...
  • Future capabilities of CME polarimetric 3D reconstructions with the METIS instrument : a numerical test 

    Pagano, Paolo; Bemporad, A; Mackay, Duncan Hendry (2015-10) - Journal article
    Context. Understanding the 3D structure of coronal mass ejections (CMEs) is crucial for understanding the nature and origin of solar eruptions. However, owing to the optical thinness of the solar corona we can only observe ...
  • Grand challenges in protoplanetary disc modelling 

    Haworth, Thomas J.; Ilee, John D.; Forgan, Duncan H.; Facchini, Stefano; Price, Daniel J.; Boneberg, Dominika M.; Booth, Richard A.; Clarke, Cathie J.; Gonzalez, Jean-François; Hutchison, Mark A.; Kamp, Inga; Laibe, Guillaume; Lyra, Wladimir; Meru, Farzana; Mohanty, Subhanjoy; Panić, Olja; Rice, Ken; Suzuki, Takeru; Teague, Richard; Walsh, Catherine; Woitke, Peter (2016) - Journal article
    The Protoplanetary Discussions conference—held in Edinburgh, UK, from 2016 March 7th–11th—included several open sessions led by participants. This paper reports on the discussions collectively concerned with the multi-physics ...
  • 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 ...