A reduced-gravity model of the abyssal circulation with Newtonian cooling and horizontal diffusion

Akira Masuda, Katsuto Uehara

    Research output: Contribution to journalArticle

    17 Citations (Scopus)

    Abstract

    Steady abyssal circulation is investigated with a simple reduced-gravity model where horizontal diffusion of interfacial displacement is taken into account in addition to ordinary vertical diffusion of Newtonian cooling. The horizontal diffusion and viscosity turn out to change the structure of boundary layers and the field of vertical velocity both on f{hook}- and β-planes. The dynamics of western boundary layers is classified into the viscous and diffusive regimes. In either regime, horizontal diffusion dominates the distribution of vertical velocity. Downwelling prevails in the western offshore boundary current flowing equatorward, while upwelling is always found in the poleward current. A more intense, opposite vertical motion occurs in a narrower boundary layer horizontal diffusion again plays a crucial role in determining both horizontal and vertical velocities. The present model explains this downwelling in terms of the diffusion of the thickness term in potential vorticity. It is shown that only when the horizontal diffusion is incorporated is the reduced-gravity model capable of reproducing the complicated distribution of vertical velocity in the abyssal layer which has been repeatedly reported in various three-dimensional experiments. The present model is also applicable to the surface layer, extending the Sverdrup-Stommel-Munk theory of the homogeneous ocean to that more suitable for the stratified ocean.

    Original languageEnglish
    Pages (from-to)1453-1479
    Number of pages27
    JournalDeep Sea Research Part A, Oceanographic Research Papers
    Volume39
    Issue number9
    DOIs
    Publication statusPublished - Jan 1 1992

    Fingerprint

    abyssal circulation
    gravity
    cooling
    boundary layer
    downwelling
    boundary current
    ocean
    potential vorticity
    surface layer
    upwelling
    viscosity

    All Science Journal Classification (ASJC) codes

    • Environmental Science(all)
    • Earth and Planetary Sciences(all)

    Cite this

    A reduced-gravity model of the abyssal circulation with Newtonian cooling and horizontal diffusion. / Masuda, Akira; Uehara, Katsuto.

    In: Deep Sea Research Part A, Oceanographic Research Papers, Vol. 39, No. 9, 01.01.1992, p. 1453-1479.

    Research output: Contribution to journalArticle

    @article{5a2a9479915d494fa8e1650ccaaf19c3,
    title = "A reduced-gravity model of the abyssal circulation with Newtonian cooling and horizontal diffusion",
    abstract = "Steady abyssal circulation is investigated with a simple reduced-gravity model where horizontal diffusion of interfacial displacement is taken into account in addition to ordinary vertical diffusion of Newtonian cooling. The horizontal diffusion and viscosity turn out to change the structure of boundary layers and the field of vertical velocity both on f{hook}- and β-planes. The dynamics of western boundary layers is classified into the viscous and diffusive regimes. In either regime, horizontal diffusion dominates the distribution of vertical velocity. Downwelling prevails in the western offshore boundary current flowing equatorward, while upwelling is always found in the poleward current. A more intense, opposite vertical motion occurs in a narrower boundary layer horizontal diffusion again plays a crucial role in determining both horizontal and vertical velocities. The present model explains this downwelling in terms of the diffusion of the thickness term in potential vorticity. It is shown that only when the horizontal diffusion is incorporated is the reduced-gravity model capable of reproducing the complicated distribution of vertical velocity in the abyssal layer which has been repeatedly reported in various three-dimensional experiments. The present model is also applicable to the surface layer, extending the Sverdrup-Stommel-Munk theory of the homogeneous ocean to that more suitable for the stratified ocean.",
    author = "Akira Masuda and Katsuto Uehara",
    year = "1992",
    month = "1",
    day = "1",
    doi = "10.1016/0198-0149(92)90042-R",
    language = "English",
    volume = "39",
    pages = "1453--1479",
    journal = "Deep-Sea Research, Part A: Oceanographic Research Papers",
    issn = "0198-0149",
    publisher = "Pergamon Press Ltd.",
    number = "9",

    }

    TY - JOUR

    T1 - A reduced-gravity model of the abyssal circulation with Newtonian cooling and horizontal diffusion

    AU - Masuda, Akira

    AU - Uehara, Katsuto

    PY - 1992/1/1

    Y1 - 1992/1/1

    N2 - Steady abyssal circulation is investigated with a simple reduced-gravity model where horizontal diffusion of interfacial displacement is taken into account in addition to ordinary vertical diffusion of Newtonian cooling. The horizontal diffusion and viscosity turn out to change the structure of boundary layers and the field of vertical velocity both on f{hook}- and β-planes. The dynamics of western boundary layers is classified into the viscous and diffusive regimes. In either regime, horizontal diffusion dominates the distribution of vertical velocity. Downwelling prevails in the western offshore boundary current flowing equatorward, while upwelling is always found in the poleward current. A more intense, opposite vertical motion occurs in a narrower boundary layer horizontal diffusion again plays a crucial role in determining both horizontal and vertical velocities. The present model explains this downwelling in terms of the diffusion of the thickness term in potential vorticity. It is shown that only when the horizontal diffusion is incorporated is the reduced-gravity model capable of reproducing the complicated distribution of vertical velocity in the abyssal layer which has been repeatedly reported in various three-dimensional experiments. The present model is also applicable to the surface layer, extending the Sverdrup-Stommel-Munk theory of the homogeneous ocean to that more suitable for the stratified ocean.

    AB - Steady abyssal circulation is investigated with a simple reduced-gravity model where horizontal diffusion of interfacial displacement is taken into account in addition to ordinary vertical diffusion of Newtonian cooling. The horizontal diffusion and viscosity turn out to change the structure of boundary layers and the field of vertical velocity both on f{hook}- and β-planes. The dynamics of western boundary layers is classified into the viscous and diffusive regimes. In either regime, horizontal diffusion dominates the distribution of vertical velocity. Downwelling prevails in the western offshore boundary current flowing equatorward, while upwelling is always found in the poleward current. A more intense, opposite vertical motion occurs in a narrower boundary layer horizontal diffusion again plays a crucial role in determining both horizontal and vertical velocities. The present model explains this downwelling in terms of the diffusion of the thickness term in potential vorticity. It is shown that only when the horizontal diffusion is incorporated is the reduced-gravity model capable of reproducing the complicated distribution of vertical velocity in the abyssal layer which has been repeatedly reported in various three-dimensional experiments. The present model is also applicable to the surface layer, extending the Sverdrup-Stommel-Munk theory of the homogeneous ocean to that more suitable for the stratified ocean.

    UR - http://www.scopus.com/inward/record.url?scp=0027035859&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0027035859&partnerID=8YFLogxK

    U2 - 10.1016/0198-0149(92)90042-R

    DO - 10.1016/0198-0149(92)90042-R

    M3 - Article

    AN - SCOPUS:0027035859

    VL - 39

    SP - 1453

    EP - 1479

    JO - Deep-Sea Research, Part A: Oceanographic Research Papers

    JF - Deep-Sea Research, Part A: Oceanographic Research Papers

    SN - 0198-0149

    IS - 9

    ER -