Now showing items 42-61 of 255

  • The detection of numerous magnetic separators in a three-dimensional magnetohydrodynamic model of solar emerging flux 

    Parnell, Clare Elizabeth; Maclean, Rhona Claire; Haynes, Andrew Lewis (2010-12-20) - Journal item
    Magnetic separators in three-dimensional (3D) magnetic fields are believed to be often associated with locations of magnetic reconnection. In this preliminary study, we investigate this relationship using data from a ...
  • Detection of supersonic downflows and associated heating events in the transition region above sunspots 

    Kleint, L.; Antolin, P.; Tian, H.; Judge, P.; Testa, P.; De Pontieu, B.; Martínez-Sykora, J.; Reeves, K. K.; Wuelser, J. P.; McKillop, S.; Saar, S.; Carlsson, M.; Boerner, P.; Hurlburt, N.; Lemen, J.; Tarbell, T. D.; Title, A.; Golub, L.; Hansteen, V.; Jaeggli, S.; Kankelborg, C. (2014-06-27) - Journal article
    Interface Region Imaging Spectrograph data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0″33. On 2013 August 30, we observed bursts of high Doppler shifts suggesting strong ...
  • 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 ...
  • 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 ...
  • Dynamical patterns of coexisting strategies in a hybrid discrete-continuum spatial evolutionary game model 

    Burgess, A. E. F; Schofield, P. G.; Hubbard, S. F.; Chaplain, Mark A. J.; Lorenzi, T. (2016-12-07) - Journal article
    We present a novel hybrid modelling framework that takes into account two aspects which have been largely neglected in previous models of spatial evolutionary games: random motion and chemotaxis. A stochastic individual-based ...
  • Effect of collisions on amplification of laser beams by Brillouin scattering in plasmas 

    Humphrey, K. A.; Trines, R. M. G. M.; Fiuza, F.; Speirs, D. C.; Norreys, P.; Cairns, R. A.; Silva, L. O.; Bingham, R. (2013-10) - Journal article
    We report on particle in cell simulations of energy transfer between a laser pump beam and a counter-propagating seed beam using the Brillouin scattering process in uniform plasma including collisions. The results presented ...
  • 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 effect of interstitial pressure on therapeutic agent transport : coupling with the tumor blood and lymphatic vascular systems 

    Wu, Min; Frieboes, Hermann B.; Chaplain, Mark A. J.; McDougall, Steven R.; Cristini, Vittorio; Lowengrub, John S. (2014-08-21) - Journal article
    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic ...
  • Effect of Prandtl's ration on balance in geophysical turbulence 

    Dritschel, David Gerard; McKiver, William Joseph (2015-07-21) - Journal article
    The fluid dynamics of the atmosphere and oceans are to a large extent controlled by the slow evolution of a scalar field called ‘potential vorticity’, with relatively fast motions such as inertia-gravity waves playing only ...
  • The effect of slip length on vortex rebound from a rigid boundary 

    Sutherland, D.; Macaskill, C.; Dritschel, D.G. (2013-09-23) - Journal article
    The problem of a dipole incident normally on a rigid boundary, for moderate to large Reynolds numbers, has recently been treated numerically using a volume penalisation method by Nguyen van yen, Farge, and Schneider [Phys. ...
  • The effects of line-of-sight integration on multistrand coronal loop oscillations 

    De Moortel, Ineke; Pascoe, David James (2012-02-10) - Journal article
  • Effects of M dwarf magnetic fields on potentially habitable planets 

    Vidotto, A.A.; Jardine, M.; Morin, J.; Donati, J.-F.; Lang, P.; Russell, A.J.B. (2013-09-02) - Journal article
    We investigate the effect of the magnetic fields of M dwarf (dM) stars on potentially habitable Earth-like planets. These fields can reduce the size of planetary magnetospheres to such an extent that a significant fraction ...
  • Effects of thermal conduction and compressive viscosity on the period ratio of the slow mode 

    Macnamara, Cicely Krystyna; Roberts, Bernard (2010-06) - Journal article
    Aims: Increasing observational evidence of wave modes brings us to a closer understanding of the solar corona. Coronal seismology allows us to combine wave observations and theory to determine otherwise unknown parameters. ...
  • Ellipsoidal vortices in rotating stratified fluids : beyond the quasi-geostrophic approximation 

    Tsang, Yue-Kin; Dritschel, David G. (2015-01) - Journal article
    We examine the basic properties and stability of isolated vortices having uniform potential vorticity (PV) in a non-hydrostatic rotating stratified fluid, under the Boussinesq approximation. For simplicity, we consider a ...
  • 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 energy budget of stellar magnetic fields : comparing non-potential simulations and observations 

    Lehmann, L. T.; Jardine, M. M.; Vidotto, A. A.; Mackay, D. H.; See, Wyke Chun Victor; Donati, J. -F.; Folsom, C. P.; Jeffers, S. V.; Marsden, Steve; Morin, J.; Petit, P. (2017-03-21) - Journal article
    The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic field topology at ...
  • The energy budget of stellar magnetic fields : comparing non-potential simulations and observations 

    Lehmann, L. T.; Jardine, M. M.; Vidotto, A. A.; Mackay, D. H.; See, V.; Donati, J.-F.; Folsom, C. P.; Jeffers, S. V.; Marsden, S. C.; Morin, J.; Petit, P. (2016-10-27) - Journal article
    The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic fieldt opology at ...
  • Energy dissipation and resolution of steep gradients in one-dimensional Burgers flows 

    Tran, Chuong Van; Dritschel, David Gerard (2010-03) - Journal article
    Traveling-wave solutions of the inviscid Burgers equation having smooth initial wave profiles of suitable shapes are known to develop shocks (infinite gradients) in finite times. Such singular solutions are characterized ...
  • Ergodicity and spectral cascades in point vortex flows on the sphere 

    Dritschel, D.G.; Lucia, M.; Poje, A.C. (2015-06-29) - Journal article
    We present results for the equilibrium statistics and dynamic evolution of moderately large [n=O(102-103)] numbers of interacting point vortices on the sphere under the constraint of zero mean angular momentum. For systems ...