The Ocean Boundary Layer beneath Larsen C Ice Shelf: Insights from Large-Eddy Simulations with a Near-Wall Model

被引:8
作者
Vreugdenhil, Catherine A. [1 ,2 ]
Taylor, John R. [1 ]
Davis, Peter E. D. [3 ]
Nicholls, Keith W. [3 ]
Holland, Paul R. [3 ]
Jenkins, Adrian [4 ]
机构
[1] Univ Cambridge, Cambridge, England
[2] Univ Melbourne, Melbourne, Vic, Australia
[3] British Antarctic Survey, Cambridge, England
[4] Northumbria Univ, Newcastle Upon Tyne, England
关键词
Ice shelves; Ocean dynamics; Turbulence; Mixing; Tides; MELT RATE; TURBULENT; INSTABILITY; DRIVEN; CONVECTION; ABLATION; SURFACE; VARIABILITY; DISSOLUTION; FLOWS;
D O I
10.1175/JPO-D-21-0166.1
中图分类号
P7 [海洋学];
学科分类号
0707 ;
摘要
The melt rate of Antarctic ice shelves is of key importance for rising sea levels and future climate scenarios. Recent observations beneath Larsen C Ice Shelf revealed an ocean boundary layer that was highly turbulent and raised questions on the effect of these rich flow dynamics on the ocean heat transfer and the ice shelf melt rate. Directly motivated by the field observations, we have conducted large-eddy simulations (LES) to further examine the ocean boundary layer beneath Larsen C Ice Shelf. The LES was initialized with uniform temperature and salinity (T-S) and included a realistic tidal cycle and a small basal slope. A new parameterization based on previous work was applied at the top boundary to model near-wall turbulence and basal melting. The resulting vertical T-S profiles, melt rate, and friction velocity matched well with the Larsen C Ice Shelf observations. The instantaneous melt rate varied strongly with the tidal cycle, with faster flow increasing the turbulence and mixing of heat toward the ice base. An Ekman layer formed beneath the ice base and, due to the strong vertical shear of the current, Ekman rolls appeared in the mixed layer and stratified region (depth approximate to 20-60 m). In an additional high-resolution simulation (conducted with a smaller domain) the Ekman rolls were associated with increased turbulent kinetic energy, but a relatively small vertical heat flux. Our results will help with interpreting field observations and parameterizing the ocean-driven basal melting of ice shelves.
引用
收藏
页码:1903 / 1926
页数:24
相关论文
共 71 条
  • [1] Large-Eddy Simulation of Thermally Stratified Atmospheric Boundary-Layer Flow Using a Minimum Dissipation Model
    Abkar, Mahdi
    Moin, Parviz
    [J]. BOUNDARY-LAYER METEOROLOGY, 2017, 165 (03) : 405 - 419
  • [2] [Anonymous], 2008, THESIS
  • [3] Ocean variability contributing to basal melt rate near the ice front of Ross Ice Shelf, Antarctica
    Arzeno, Isabella B.
    Beardsley, Robert C.
    Limeburner, Richard
    Owens, Breck
    Padman, Laurie
    Springer, Scott R.
    Stewart, Craig L.
    Williams, Michael J. M.
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 2014, 119 (07) : 4214 - 4233
  • [4] Bathmann U., 1994, BERICHTE POLARFORSCH, V135
  • [5] Ocean Stratification and Low Melt Rates at the Ross Ice Shelf Grounding Zone
    Begeman, Carolyn Branecky
    Tulaczyk, Slawek M.
    Marsh, Oliver J.
    Mikucki, Jill A.
    Stanton, Timothy P.
    Hodson, Timothy O.
    Siegfried, Matthew R.
    Powell, Ross D.
    Christianson, Knut
    King, Matt A.
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 2018, 123 (10) : 7438 - 7452
  • [6] THE LAW OF THE WALL IN TURBULENT-FLOW
    BRADSHAW, P
    HUANG, GP
    [J]. PROCEEDINGS OF THE ROYAL SOCIETY-MATHEMATICAL AND PHYSICAL SCIENCES, 1995, 451 (1941): : 165 - 188
  • [7] BROWN RA, 1972, J ATMOS SCI, V29, P850, DOI 10.1175/1520-0469(1972)029<0850:OTIPIO>2.0.CO
  • [8] 2
  • [9] BUSINGER JA, 1971, J ATMOS SCI, V28, P181, DOI 10.1175/1520-0469(1971)028<0181:FPRITA>2.0.CO
  • [10] 2