Browsing by Subject "Waves"

Now showing items 1-20 of 22

  • 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. ...

  • Contribution of mode-coupling and phase-mixing of Alfvén waves to coronal heating 

    Pagano, P.; De Moortel, I. (2017-05-12) - Journal article
    Context. Phase-mixing of Alfvén waves in the solar corona has been identified as one possible candidate to explain coronal heating. While this scenario is supported by observations of ubiquitous oscillations in the corona ...

  • 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 ...

  • The effects of line-of-sight integration on multistrand coronal loop oscillations 

    De Moortel, Ineke; Pascoe, David James (2012-02-10) - Journal article

  • 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 ...

  • Forward modeling of gyrosynchrotron intensity perturbations by sausage modes 

    Reznikova, V. E.; Antolin, P.; Van Doorsselaere, T. (2014-03-28) - Journal article
    To determine the observable radio signatures of the fast sausagestanding wave, we examine gyrosynchrotron (GS) emission modulation usinga linear three-dimensional magnetohydrodynamic model of a plasmacylinder. Effects of ...

  • Forward modeling of standing slow modes in flaring coronal loops 

    Yuan, D.; Van Doorsselaere, T.; Banerjee, D.; Antolin, P. (2015-07-02) - Journal article
    Standing slow-mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Owing to the lack of spatial information, ...

  • 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 ...

  • Magnetohydrodynamic kink waves in two-dimensional non-uniform prominence threads 

    Arregui, I; Soler, R; Ballester, J.; Wright, Andrew Nicholas (2011-09) - Journal article
    Aims. We analyse the oscillatory properties of resonantly damped transverse kink oscillations in two-dimensional prominence threads. Methods. The fine structures are modelled as cylindrically symmetric magnetic flux tubes ...

  • Magnetohydrodynamic waves in structured atmospheres 

    Edwin, Patricia Mary (University of St Andrews, 1985) - Thesis
    The effect of structuring, in the form of magnetic or density inhomogeneities, on the magnetohydrodynamic (mhd) waves of an infinite plasma is investigated. The appropriate dispersion formulae, in both Cartesian and ...

  • MHD mode conversion of fast and slow magnetoacoustic waves in the solar corona 

    McDougall-Bagnall, A. M. Dee (University of St Andrews, 2010-11-30) - Thesis
    There are three main wave types present in the Sun’s atmosphere: Alfvén waves and fast and slow magnetoacoustic waves. Alfvén waves are purely magnetic and would not exist if it was not for the Sun’s magnetic field. The ...

  • The multi-thermal and multi-stranded nature of coronal rain 

    Antolin, P.; Vissers, G.; Pereira, T. M. D.; Rouppe van der Voort, L.; Scullion, E. (2015-06-09) - Journal article
    We analyze coordinated observations of coronal rain in loops, spanning chromospheric, transition region (TR), and coronal temperatures with sub-arcsecond spatial resolution. Coronal rain is found to be a highly multithermal ...

  • Observational signatures of waves and flows in the solar corona 

    De Moortel, I.; Antolin, Patrick; Van Doorsselaere, T. (2015-02-01) - Journal article
    Propagating perturbations have been observed in extended coronal loop structures for a number of years, but the interpretation in terms of slow (propagating) magneto-acoustic waves and/or as quasi-periodic upflows remains ...

  • On the parallel and perpendicular propagating motions visible in polar plumes : an incubator for (fast) solar wind acceleration? 

    Liu, Jiajia; McIntosh, Scott W.; De Moortel, Ineke; Wang, Yuming (2015-06-20) - Journal article
    We combine observations of the Coronal Multi-channel Polarimeter and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory to study the characteristic properties of (propagating) Alfvenic motions and ...

  • Phase mixing of nonlinear visco-resistive Alfvén waves 

    McLaughlin, James Alexander; De Moortel, Ineke; Hood, Alan William (2011-02) - Journal article
    Aims: We investigate the behaviour of nonlinear, nonideal Alfvén wave propagation within an inhomogeneous magnetic environment. Methods: The governing MHD equations are solved in 1D and 2D using both analytical techniques ...

  • Propagating coupled Alfvén and kink oscillations in an arbitrary inhomogeneous corona 

    Pascoe, David James; Wright, Andrew Nicholas; De Moortel, Ineke (2011-04-10) - Journal article
    Observations have revealed ubiquitous transverse velocity perturbation waves propagating in the solar corona. We perform three-dimensional numerical simulations of footpoint-driven transverse waves propagating in a low β ...

  • Resonant absorption of transverse oscillations and associated heating in a solar prominence. I. Observational aspects 

    Okamoto, Takenori J.; Antolin, Patrick; De Pontieu, Bart; Uitenbroek, Han; Van Doorsselaere, Tom; Yokoyama, Takaaki (2015-08-11) - Journal article
    Transverse magnetohydrodynamic waves have been shown to be ubiquitous in the solar atmosphere and can, in principle, carry sufficient energy to generate and maintain the Sun's million-degree outer atmosphere or corona. ...

  • Standing kink modes in three-dimensional coronal loops 

    De Moortel, Ineke; Pascoe, David James (2014-03-11) - Journal article
    So far, the straight flux tube model proposed by Edwin & Roberts is the most commonly used tool in practical coronal seismology, in particular, to infer values of the (coronal) magnetic field from observed, standing kink ...

  • Statistical evidence for the existence of Alfvénic turbulence in solar coronal loops 

    Liu, J.; Mcintosh, S.W.; De Moortel, I.; Threlfall, J.; Bethge, C. (2014-12-10) - Journal article
    Recent observations have demonstrated that waves capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which timescales and ...

  • Theoretical foundation of 3D Alfvén resonances : normal modes 

    Wright, Andrew Nicholas; Elsden, Thomas William (2016-12-20) - Journal article
    We consider the resonant coupling of fast and Alfvén magnetohydrodynamic (MHD) waves in a 3D equilibrium. Numerical solutions to normal modes (∝ exp(−iωt)) are presented along with a theoretical framework to interpret them. ...