Skip to content

Research at St Andrews

Head on collisions between two quasi-geostrophic hetons in a continuously stratified fluid

Research output: Contribution to journalArticle

DOI

Open Access permissions

Open

Author(s)

Jean Noel Reinaud, Xavier Carton

School/Research organisations

Abstract

We examine the interactions between two three-dimensional quasi-geostrophic hetons. The hetons are initially translating towards one another. We address the effect of the vertical distance between the two poles (vortices) constituting each heton, on the interaction. We also examine the influence of the horizontal separation between the poles within each heton. In this investigation, the two hetons are facing each other. Two configurations are possible depending on the respective location of the like-signed poles of the hetons. When they lie at the same depth, we refer to the configuration as symmetric; the anti-symmetric configuration corresponds to opposite-signed poles at the same depth. The first step in the investigation uses point vortices to represent the poles of the hetons. This approach allows to rapidly browse the parameter space and to estimate the possible heton trajectories. For a symmetric pair, hetons either reverse their trajectory or recombine and escape perpendicularly depending of their horizontal and vertical offsets. On the other hand, anti-symmetric hetons recombine and escape perpendicularly as same-depth dipoles. In a second part, we focus on finite core hetons (with finite volume poles). These hetons can deform and may be sensitive to horizontal shear induced deformations, or to baroclinic instability. These destabilisations depend on the vertical and horizontal offsets between the various poles, as well as on their width-to-height aspect ratios. They can modify the volume of the poles via vortex merger, breaking and/or shearing out; they compete with the advective evolution observed for singular (point) vortices. Importantly, hetons can break down or re-configure before they can drift away as expected from a point vortex approach. Thus a large variety of behaviours is observed in the parameter space. Finally, we briefly illustrate the behaviour of tall hetons which can be unstable to an azimuthal mode l=1 when many vertical modes of deformation are present on the heton.

Close

Details

Original languageEnglish
Pages (from-to)144-180
Number of pages37
JournalJournal of Fluid Mechanics
Volume779
Early online date14 Aug 2015
DOIs
Publication statusPublished - Sep 2015

    Research areas

  • Geophysical and geological flows, Quasi-geostrophic flows, Vortex dynamics

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Three-dimensional quasi-geostrophic vortex equilibria with m−fold symmetry

    Reinaud, J. N., 25 Mar 2019, In : Journal of Fluid Mechanics. 863, p. 32-59

    Research output: Contribution to journalArticle

  2. The stability and nonlinear evolution of quasi-geostrophic toroidal vortices

    Reinaud, J. N. & Dritschel, D. G., 25 Mar 2019, In : Journal of Fluid Mechanics. 863, p. 60-78

    Research output: Contribution to journalArticle

  3. Entrapping of a vortex pair interacting with a fixed point vortex revisited. II. Finite size vortices and the effect of deformation

    Reinaud, J. N., Koshel, K. V. & Ryzhov, E. A., 28 Sep 2018, In : Physics of Fluids. 30, 9, 10 p., 096604.

    Research output: Contribution to journalArticle

  4. Entrapping of a vortex pair interacting with a fixed point vortex revisited. I. Point vortices

    Koshel, K. V., Reinaud, J. N., Riccardi, G. & Ryzhov, E. A., 28 Sep 2018, In : Physics of Fluids. 30, 9, 096603.

    Research output: Contribution to journalArticle

  5. The merger of geophysical vortices at finite Rossby and Froude number

    Reinaud, J. N. & Dritschel, D. G., 10 Aug 2018, In : Journal of Fluid Mechanics. 848, p. 388-410

    Research output: Contribution to journalArticle

Related by journal

  1. Journal of Fluid Mechanics (Journal)

    David Gerard Dritschel (Editor)
    2005 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

Related by journal

  1. On the regularity of the Green-Naghdi equations for a rotating shallow fluid layer

    Dritschel, D. G. & Jalali, M. R., 25 Apr 2019, In : Journal of Fluid Mechanics. 865, p. 100-136

    Research output: Contribution to journalArticle

  2. Scale-invariant singularity of the surface quasigeostrophic patch

    Scott, R. K. & Dritschel, D. G., 25 Mar 2019, In : Journal of Fluid Mechanics. 863, 12 p., R2.

    Research output: Contribution to journalArticle

  3. The stability and nonlinear evolution of quasi-geostrophic toroidal vortices

    Reinaud, J. N. & Dritschel, D. G., 25 Mar 2019, In : Journal of Fluid Mechanics. 863, p. 60-78

    Research output: Contribution to journalArticle

  4. Three-dimensional quasi-geostrophic vortex equilibria with m−fold symmetry

    Reinaud, J. N., 25 Mar 2019, In : Journal of Fluid Mechanics. 863, p. 32-59

    Research output: Contribution to journalArticle

ID: 204227292