Now showing items 1-8 of 8

  • Bending and twisting instabilities of columnar elliptical vortices in a rotating strongly stratified fluid 

    Billant, Paul; Dritschel, David Gerard; Chomaz, Jean-Marc (2006-08-25) - Journal article
    In this paper, we investigate the three-dimensional stability of the Moore-Saffman elliptical vortex in a rotating stratified fluid. By means of an asymptotic analysis for long vertical wavelength perturbations and small ...
  • The critical merger distance between two co-rotating quasi-geostrophic vortices 

    Reinaud, Jean Noel; Dritschel, David Gerard (2005-01-10) - Journal article
    This paper examines the critical merger or strong interaction distance between two equal-potential-vorticity quasi-geostrophic vortices. The interaction between the two vortices depends on five parameters: their volume ...
  • The merger of vertically offset quasi-geostrophic vortices 

    Reinaud, Jean Noel; Dritschel, David Gerard (2002-10-25) - Journal article
    We examine the critical merging distance between two equal-volume, equal-potential-vorticity quasi-geostrophic vortices. We focus on how this distance depends on the vertical offset between the two vortices, each having a ...
  • 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 ...
  • The quasi-geostrophic ellipsoidal vortex model 

    Dritschel, David Gerard; Reinaud, Jean Noel; McKiver, William J (2004-04-25) - Journal article
    We present a simple approximate model for studying general aspects of vortex interactions in a rotating stably-stratified fluid. The model idealizes vortices by ellipsoidal volumes of uniform potential vorticity, a materially ...
  • Quasi-geostrophic shallow-water doubly-connected vortex equilibria and their stability 

    Plotka, Hanna; Dritschel, David Gerard (2013-05) - Journal article
    We examine the form, properties, stability and evolution of doubly-connected (two-vortex) relative equilibria in the single-layer ƒ-plane quasi-geostrophic shallow-water model of geophysical fluid dynamics. Three parameters ...
  • Quasi-geostrophic vortices in compressible atmospheres 

    Scott, Richard Kirkness; Dritschel, David Gerard (2005-05-10) - Journal article
    This paper considers the effect of an exponential variation in the background density field (as exists in compressible atmospheres) on the structure and dynamics of the quasi-geostrophic system, and compares the results ...
  • The shape of vortices in quasi-geostrophic turbulence 

    Reinaud, Jean Noel; Dritschel, David Gerard; Koudella, CR (2003-01-10) - Journal article
    The present work discusses the most commonly occurring shape of the coherent vortical structures in rapidly rotating stably stratified turbulence, under the quasi-geostrophic approximation. In decaying turbulence, these ...