Physical model of bathymetric effects on the antarctic circumpolar current

Don L. Boyer, Rui-Rong Chen, Lijun Tao, Peter A. Davies

    Research output: Contribution to journalArticle

    6 Citations (Scopus)

    Abstract

    Laboratory experiments were conducted to simulate some of the effects of the bathymetry of the southern ocean on the physical characteristics of the Antarctic Circumpolar Current (ACC). An idealized zonal wind stress, which varied inversely with the distance from the model Antarctic continent, was simulated in the laboratory model by a radially inward sink-source flow in a thin layer along the surface of the circular test cell. The experiments demonstrated the feasibility of simulating the surface wind stress in physical models by source-sink forcing. The present model, however, has the limitation of not accounting for such factors as the longitudinal variations in the wind shear and the decrease in wind stress on approaching the Antarctic continent from the north. Planetary beta effects were neglected because the topographic beta term can be shown to dominate over large portions of the model area. The neglect of beta effects is also a limitation of the model. In spite of these limitations, however, the simulations of the physical model for both the homogeneous and linearly stratified cases were shown to be in good agreement with observations of the ACC. These include well-defined strong currents along the mid-ocean ridge; strong perturbations in the vicinity of the Macquarie Ridge, Campbell Plateau, and Kerguelen Gaussberg Plateau; strong meridional transport to the east of the Drake Passage; and anomalies to the south (wave troughs) and to the north (wave ridges) of the main circumpolar current over ocean basins and mountain ridges, respectively. It was shown that the Eltanin and Udintsev fracture zones in the vicinity of 135-degrees-W are important factors in directing the ACC eastward across the Southeast Pacific Basin to the Drake Passage. The model results suggest that these fracture zones can influence the nature of the flow in the western Atlantic because of their control of the flow through the Drake Passage. The estimated volume transports through the Drake Passage based on the model results are in fair agreement with oceanic observations. Estimates of the spin-up time of the system for homogeneous and stratified cases have been provided.

    Original languageEnglish
    Pages (from-to)2587-2608
    Number of pages22
    JournalJournal of Geophysical Research: Oceans
    Volume98
    Issue numberC2
    DOIs
    Publication statusPublished - 1993

    Keywords

    • TOPOGRAPHY
    • STRATIFIED OCEAN
    • LARGE-SCALE
    • FLOW
    • WIND-DRIVEN
    • SPIN-UP
    • SURFACE CIRCULATION
    • SOUTHERN-OCEAN

    Cite this

    Boyer, Don L. ; Chen, Rui-Rong ; Tao, Lijun ; Davies, Peter A. / Physical model of bathymetric effects on the antarctic circumpolar current. In: Journal of Geophysical Research: Oceans . 1993 ; Vol. 98, No. C2. pp. 2587-2608.
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    abstract = "Laboratory experiments were conducted to simulate some of the effects of the bathymetry of the southern ocean on the physical characteristics of the Antarctic Circumpolar Current (ACC). An idealized zonal wind stress, which varied inversely with the distance from the model Antarctic continent, was simulated in the laboratory model by a radially inward sink-source flow in a thin layer along the surface of the circular test cell. The experiments demonstrated the feasibility of simulating the surface wind stress in physical models by source-sink forcing. The present model, however, has the limitation of not accounting for such factors as the longitudinal variations in the wind shear and the decrease in wind stress on approaching the Antarctic continent from the north. Planetary beta effects were neglected because the topographic beta term can be shown to dominate over large portions of the model area. The neglect of beta effects is also a limitation of the model. In spite of these limitations, however, the simulations of the physical model for both the homogeneous and linearly stratified cases were shown to be in good agreement with observations of the ACC. These include well-defined strong currents along the mid-ocean ridge; strong perturbations in the vicinity of the Macquarie Ridge, Campbell Plateau, and Kerguelen Gaussberg Plateau; strong meridional transport to the east of the Drake Passage; and anomalies to the south (wave troughs) and to the north (wave ridges) of the main circumpolar current over ocean basins and mountain ridges, respectively. It was shown that the Eltanin and Udintsev fracture zones in the vicinity of 135-degrees-W are important factors in directing the ACC eastward across the Southeast Pacific Basin to the Drake Passage. The model results suggest that these fracture zones can influence the nature of the flow in the western Atlantic because of their control of the flow through the Drake Passage. The estimated volume transports through the Drake Passage based on the model results are in fair agreement with oceanic observations. Estimates of the spin-up time of the system for homogeneous and stratified cases have been provided.",
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    Physical model of bathymetric effects on the antarctic circumpolar current. / Boyer, Don L.; Chen, Rui-Rong; Tao, Lijun; Davies, Peter A.

    In: Journal of Geophysical Research: Oceans , Vol. 98, No. C2, 1993, p. 2587-2608.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Physical model of bathymetric effects on the antarctic circumpolar current

    AU - Boyer, Don L.

    AU - Chen, Rui-Rong

    AU - Tao, Lijun

    AU - Davies, Peter A.

    PY - 1993

    Y1 - 1993

    N2 - Laboratory experiments were conducted to simulate some of the effects of the bathymetry of the southern ocean on the physical characteristics of the Antarctic Circumpolar Current (ACC). An idealized zonal wind stress, which varied inversely with the distance from the model Antarctic continent, was simulated in the laboratory model by a radially inward sink-source flow in a thin layer along the surface of the circular test cell. The experiments demonstrated the feasibility of simulating the surface wind stress in physical models by source-sink forcing. The present model, however, has the limitation of not accounting for such factors as the longitudinal variations in the wind shear and the decrease in wind stress on approaching the Antarctic continent from the north. Planetary beta effects were neglected because the topographic beta term can be shown to dominate over large portions of the model area. The neglect of beta effects is also a limitation of the model. In spite of these limitations, however, the simulations of the physical model for both the homogeneous and linearly stratified cases were shown to be in good agreement with observations of the ACC. These include well-defined strong currents along the mid-ocean ridge; strong perturbations in the vicinity of the Macquarie Ridge, Campbell Plateau, and Kerguelen Gaussberg Plateau; strong meridional transport to the east of the Drake Passage; and anomalies to the south (wave troughs) and to the north (wave ridges) of the main circumpolar current over ocean basins and mountain ridges, respectively. It was shown that the Eltanin and Udintsev fracture zones in the vicinity of 135-degrees-W are important factors in directing the ACC eastward across the Southeast Pacific Basin to the Drake Passage. The model results suggest that these fracture zones can influence the nature of the flow in the western Atlantic because of their control of the flow through the Drake Passage. The estimated volume transports through the Drake Passage based on the model results are in fair agreement with oceanic observations. Estimates of the spin-up time of the system for homogeneous and stratified cases have been provided.

    AB - Laboratory experiments were conducted to simulate some of the effects of the bathymetry of the southern ocean on the physical characteristics of the Antarctic Circumpolar Current (ACC). An idealized zonal wind stress, which varied inversely with the distance from the model Antarctic continent, was simulated in the laboratory model by a radially inward sink-source flow in a thin layer along the surface of the circular test cell. The experiments demonstrated the feasibility of simulating the surface wind stress in physical models by source-sink forcing. The present model, however, has the limitation of not accounting for such factors as the longitudinal variations in the wind shear and the decrease in wind stress on approaching the Antarctic continent from the north. Planetary beta effects were neglected because the topographic beta term can be shown to dominate over large portions of the model area. The neglect of beta effects is also a limitation of the model. In spite of these limitations, however, the simulations of the physical model for both the homogeneous and linearly stratified cases were shown to be in good agreement with observations of the ACC. These include well-defined strong currents along the mid-ocean ridge; strong perturbations in the vicinity of the Macquarie Ridge, Campbell Plateau, and Kerguelen Gaussberg Plateau; strong meridional transport to the east of the Drake Passage; and anomalies to the south (wave troughs) and to the north (wave ridges) of the main circumpolar current over ocean basins and mountain ridges, respectively. It was shown that the Eltanin and Udintsev fracture zones in the vicinity of 135-degrees-W are important factors in directing the ACC eastward across the Southeast Pacific Basin to the Drake Passage. The model results suggest that these fracture zones can influence the nature of the flow in the western Atlantic because of their control of the flow through the Drake Passage. The estimated volume transports through the Drake Passage based on the model results are in fair agreement with oceanic observations. Estimates of the spin-up time of the system for homogeneous and stratified cases have been provided.

    KW - TOPOGRAPHY

    KW - STRATIFIED OCEAN

    KW - LARGE-SCALE

    KW - FLOW

    KW - WIND-DRIVEN

    KW - SPIN-UP

    KW - SURFACE CIRCULATION

    KW - SOUTHERN-OCEAN

    U2 - 10.1029/92JC02254

    DO - 10.1029/92JC02254

    M3 - Article

    VL - 98

    SP - 2587

    EP - 2608

    JO - Journal of Geophysical Research: Oceans

    JF - Journal of Geophysical Research: Oceans

    SN - 2169-9275

    IS - C2

    ER -