Revisiting mesoscale eddy genesis mechanism of nonlinear advection in a marginal ice zone
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摘要: 利用三维海洋模式与二维海冰模式耦合,研究海冰边缘区域中尺度涡旋形成最重要的机制之一——非线性平流机制。二维海洋模型模拟结果表明,非线性平流机制在水深比较浅的时候更加重要。不同于把海洋考虑成一个正压流体的二维模型,三维海洋模型中海冰通过海-冰相互作用直接影响海洋表层。我们发现在三维海洋模型实验中,中尺度涡旋和海洋表面抬升都对水深变化敏感。海流速度的垂直结构表面,当海水变浅,各层海流都变得更快。相同风应力作用相同时间之后,表面抬升与海水深度成反比关系。同时我们还发现由于垂直运动,在三维海洋模型实验结果中,海面抬升非常小,只有二维海洋模型实验结果的1%。垂直运动是三维海洋模型和二维海洋模型实验结果不同的根本原因。Abstract: A three-dimensional (3-D) ocean model is coupled with a two-dimensional (2-D) sea ice model, to revisit a nonlinear advection mechanism, one of the most important mesoscale eddy genesis mechanisms in the marginal ice zone. Two-dimensional ocean model simulations suggest nonlinear advection mechanism is more important when the water gets shallower. Instead of considering the ocean as barotropic fluid in the 2-D ocean model, the 3-D ocean model allows the sea ice to affect the current directly in the surface layer via ocean-ice interaction. It is found that both mesoscale eddy and sea surface elevation are sensitive to changes in a water depth in the 3-D simulations. The vertical profile of a current velocity in 3-D experiments suggests that when the water depth gets shallower, the current move faster in each layer, which makes the sea surface elevation be nearly inverse proportional to the water depth with the same wind forcing during the same time. It is also found that because of the vertical motion, the magnitude of variations in the sea surface elevation in the 3-D simulations is very small, being only 1% of the change in the 2-D simulations. And it seems the vertical motion to be the essential reason for the differences between the 3-D and 2-D experiments.
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Key words:
- nonlinear advection /
- mesoscale eddy /
- marginal ice zone /
- ocean-ice interaction
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Dumont D, Kohout A, Bertino L. 2011. A wave-based model for the marginal ice zone including a floe breaking parameterization. J Geophys Res, 116(C4), doi: 10.1029/2010JC006682 Gula J, Molemaker M J, McWilliams J C. 2015. Topographic vorticity generation, submesoscale instability and vortex street formation in the Gulf Stream. Geophys Res Lett, 42(10):4054-4062 Häkkinen S. 1986. Coupled ice-ocean dynamics in the marginal ice zones:upwelling/downwelling and eddy generation. J Geophys Res, 91(C1):819-832 Hibler W D Ⅲ. 1979. A dynamic thermodynamic sea ice model. J Phys Oceanogr, 9(4):815-846 Hunke E C, Dukowicz J K. 1997. An elastic-viscous-plastic model for sea ice dynamics. J Phys Oceanogr, 27(9):1849-1867 Hunke E C, Zhang Y. 1999. A comparison of sea ice dynamics models at high resolution. Mon Wea Rev, 127(3):396-408 Johannessen J A, Johannessen O M, Svendsen E, et al. 1987. Mesoscale eddies in the Fram Strait marginal ice zone during the 1983 and 1984 Marginal Ice Zone Experiments. J Geophys Res, 92(C7):6754-6772 Johannessen O M, Johannessen J A, Svendsen E, et al. 1987. Ice-edge eddies in the Fram Strait marginal ice zone. Science, 236(4800):427-429 Lane E M, Restrepo J M, McWilliams J C. 2007. Wave-current interaction:a comparison of radiation-stress and vortex-force representations. J Phys Oceanogr, 37(5):1122-1141 Large W G, McWilliams J C, Doney S C. 1994. Oceanic vertical mixing:a review and a model with a nonlocal boundary layer parameterization. Rev Geophys, 32(4):363-403 Lemarié F, Kurian J, Shchepetkin A F, et al. 2012. Are there inescapable issues prohibiting the use of terrain-following coordinates in climate models?.. Ocean Modell, 42:57-79 Liu A K, Häkkinen S, Peng C Y. 1993. Wave effects on ocean-ice interaction in the marginal ice zone. J Geophys Res, 98(C6):10025-10036 Liu A K, Holt B, Vachon P W. 1991. Wave propagation in the marginal ice zone:model predictions and comparisons with buoy and synthetic aperture radar data. J Geophys Res, 96(C3):4605-4621 Liu A K, Mollo-Christensen E. 1988. Wave propagation in a solid ice pack. J Phys Oceanogr, 18(11):1702-1712 McPhee M G. 1975. Ice-ocean momentum transfer for the adjex ice model. ADJEX Bull, 29:93-111 McWilliams J C, Restrepo J M, Lane E M. 2004. An asymptotic theory for the interaction of waves and currents in coastal waters. J Fluid Mech, 511:135-178 Røed L P, O'Brien J J. 1983. A coupled ice-ocean model of upwelling in the marginal ice zone. J Geophys Res, 88(C5):2863-2872 Shchepetkin A F, McWilliams J C. 2005. The regional oceanic modeling system (ROMS):a split-explicit, free-surface, topography-following-coordinate oceanic model. Ocean Modell, 9(4):347-404 Squire V A. 2007. Of ocean waves and sea-ice revisited. Cold Reg Sci Technol, 49(2):110-133 Squire V A, Dugan J P, Wadhams P, et al. 1995. Of ocean waves and sea ice. Annu Rev Fluid Mech, 27(1):115-168 Uchiyama Y, McWilliams J C, Shchepetkin A F. 2011. Wave-current interaction in an oceanic circulation model with a vortex-force formalism:application to the surf zone. Ocean Model, 34(1–2):16-35 Wadhams P, Holt B. 1991. Waves in frazil and pancake ice and their detection in Seasat synthetic aperture radar imagery. J Geophys Res, 96(C5):8835-8852 Wadhams P, Parmiggiani F, de Carolis G. 2002. The use of SAR to measure ocean wave dispersion in frazil-pancake icefields. J Phys Oceanogr, 32(6):1721-1746 Wadhams P, Squire V A, Goodman D J, et al. 1988. The attenuation rates of ocean waves in the marginal ice zone. J Geophys Res, 93(C6):6799-6818 Williams T D, Bennetts L G, Squire V A, et al. 2013a. Wave-ice interactions in the marginal ice zone:Part 1. Theoretical foundations. Ocean Modell, 71:81-91 Williams T D, Bennetts L G, Squire V A, et al. 2013b. Wave-ice interactions in the marginal ice zone:Part 2. Numerical implementation and sensitivity studies along 1D transects of the ocean surface. Ocean Modell, 71:92-101 Yang Haijun, Dai Haijin. 2015. Effect of wind forcing on the meridional heat transport in a coupled climate model:equilibrium response. Climate Dyn, 45(5–6):1451-1470
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