Skip to content

Research at St Andrews

On the energetics of a two-layer baroclinic flow

Research output: Contribution to journalArticle

DOI

Open Access permissions

Open

Abstract

The formation, evolution and co-existence of jets and vortices in turbulent planetary atmospheres is examined using a two-layer quasi-geostrophic β -channel shallow-water model. The study in particular focuses on the vertical structure of jets. Following Panetta & Held (J. Atmos. Sci., vol. 45 (22), 1988, pp. 3354–3365), a vertical shear arising from latitudinal heating variations is imposed on the flow and maintained by thermal damping. Idealised convection between the upper and lower layers is implemented by adding cyclonic/anti-cyclonic pairs, called hetons, to the flow, though the qualitative flow evolution is evidently not sensitive to this or other small-scale stochastic forcing. A very wide range of simulations have been conducted. A characteristic simulation which exhibits alternation between two different phases, quiescent and turbulent, is examined in detail. We study the energy transfers between different components and modes, and find the classical picture of barotropic/baroclinic energy transfers to be too simplistic. We also discuss the dependence on thermal damping and on the imposed vertical shear. Both have a strong influence on the flow evolution. Thermal damping is a major factor affecting the stability of the flow while vertical shear controls the number of jets in the domain, qualitatively through the Rhines scale LRh = √U/β.
Close

Details

Original languageEnglish
Pages (from-to)586-618
Number of pages33
JournalJournal of Fluid Mechanics
Volume816
Early online date8 Mar 2017
DOIs
StatePublished - Apr 2017

    Research areas

  • Baroclinic flows, Geostrophic turbulence, Jets

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

View graph of relations

Related by author

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

    Dritschel, D. G. & Jalali, M. R. 19 Feb 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. 28 Jan 2019 In : Journal of Fluid Mechanics. 863, 12 p., R2

    Research output: Contribution to journalArticle

  3. Imperfect bifurcation for the quasi-geostrophic shallow-water equations

    Dritschel, D. G., Hmidi, T. & Renault, C. 12 Oct 2018 In : Archive for Rational Mechanics and Analysis. 231, 3, p. 1853-1915 63 p.

    Research output: Contribution to journalArticle

Related by journal

  1. Journal of Fluid Mechanics (Journal)

    Dritschel, D. G. (Editor)
    2005 → …

    Activity: Publication peer-review and editorial workEditor 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. 19 Feb 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. 28 Jan 2019 In : Journal of Fluid Mechanics. 863, 12 p., R2

    Research output: Contribution to journalArticle

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

    Reinaud, J. N. 22 Jan 2019 In : Journal of Fluid Mechanics. 863, p. 32-59

    Research output: Contribution to journalArticle

ID: 249029829