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Michael A. Spall

et al. (2001) estimate the boundary current transport approaching the ridge from the east to be 5 ± 1 Sv (where 1 Sv ≡ 10 6 m 3 s −1 ), with 3 ± 1 Sv turning back toward Fram Strait along the Lomonosov Ridge and another 3 ± 1 Sv found to the west of the ridge in the cyclonic boundary current. Fig . 1. Bottom topography and schematic of the Atlantic Water circulation in the Arctic Basin [modified from Rudels et al. (1994) and Rudels (2012) ]. The complexities of the Arctic Ocean, including

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Roy Barkan, Kraig B. Winters, and Stefan G. Llewellyn Smith

wave interactions in the interior, instability of geostrophic motions, and direct interactions with side and bottom boundaries ( Müller et al. 2005 ; Ferrari and Wunsch 2010 ). About 90% of the E k in the oceans is stored in the geostrophic eddy field ( Ferrari and Wunsch 2009 ) and, given this large fraction, we focus here on the “instability” pathway to dissipation. Geostrophic eddies are formed, primarily, via baroclinic instability of large-scale ocean currents that are in approximate

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Nicolas Grisouard and Leif N. Thomas

1. Introduction Most of the ocean’s kinetic energy is contained in the mesoscale eddy field ( Ferrari and Wunsch 2009 ), with flows characterized by the hydrostatic and geostrophic balances. Such “balanced” motions tend to aggregate into larger scales, following an inverse cascade of energy. Energy dissipation on the other hand happens at much smaller scales, and understanding how energy in balanced motions is transferred to small scales is currently the subject of intense research. Ocean

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Catherine A. Vreugdenhil, Andrew McC. Hogg, Ross W. Griffiths, and Graham O. Hughes

described by a purely advective ventilation time scale. Indeed, Marotzke and Klinger (2000) find that the ocean responds on a time scale that is governed by advection in the deep western boundary current. It is not clear what the relative roles of the advection and mixing are or to what extent these are coupled in governing adjustments of the overturning transport and stratification. We examine the relative roles of diapycnal mixing in the abyssal and upper ocean during adjustments toward long

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Jonathan Gula, M. Jeroen Molemaker, and James C. McWilliams

North Atlantic Ocean to successive child grids with Δ x ≈ 1.5 km, Δ x ≈ 500 m, and finally Δ x ≈ 150 m. The procedure is offline, one-way nesting from larger to finer scales without feedback from the child grid solution onto the parent grid ( Penven et al. 2006 ). The boundary condition algorithm consists of a modified Flather-type scheme for the barotropic mode ( Mason et al. 2010 ) and Orlanski-type scheme for the baroclinic mode (including T and S ; Marchesiello et al. 2001 ). Bathymetry

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Ryan Abernathey and Paola Cessi

eddies completely determines the stratification. The key ingredients of this problem are as follows: A zonally reentrant beta-plane channel domain, which permits a zonal current to develop. Using Cartesian coordinates ( x , y , z ), the channel dimensions are ( L x , L y , H ). Westerly wind stress forcing, which drives an Eulerian-mean overturning. The form of the wind stress is τ = τ 0 sin( πy / L y ), vanishing at the northern and southern boundaries. Surface buoyancy restoring, which

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Vamsi K. Chalamalla and Sutanu Sarkar

production during flow reversal in a stratified oscillating boundary layer on a sloping bottom. Phys. Fluids, 23, 101703 , doi: 10.1063/1.3651359 . Gayen , B. , S. Sarkar , and J. R. Taylor , 2010 : Large eddy simulation of a stratified boundary layer under an oscillatory current . J. Fluid Mech. , 643 , 233 – 266 , doi: 10.1017/S002211200999200X . Gayen , B. , G. O. Hughes , and R. W. Griffiths , 2013 : Completing the mechanical energy pathways in turbulent Rayleigh

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Peter E. Hamlington, Luke P. Van Roekel, Baylor Fox-Kemper, Keith Julien, and Gregory P. Chini

associated with boundary layer turbulence begins at approximately k = 2 π /(100 m). Near the surface, the flow remains anisotropic at small scales for both simulation cases, but at sufficient depth (as shown in Fig. 3b ) the small-scale flow is essentially isotropic. It should be noted that the vertical velocity ( w ) spectrum continues to rise for the Stokes case until the gridscale cutoff; this indicates that the small-scale resolution is marginal, but greater spatial resolution is currently

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Takeyoshi Nagai, Amit Tandon, Eric Kunze, and Amala Mahadevan

1. Introduction Most of the power into the ocean’s general circulation arises from stress exerted by the wind at the surface ( Fofonoff 1981 ; Oort et al. 1994 ; Wunsch 1998 ). Because of the ocean’s boundaries, wind patterns, density distribution, and Earth’s rotation, this energy organizes into 100–1000-km gyres and currents and fields of 10–100-km mesoscale eddies. This large-scale quasigeostrophic dynamics arrests transfer of energy to smaller scales where it could be dissipated, instead

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Carlowen A. Smith, Kevin G. Speer, and Ross W. Griffiths

the scaling analysis and report in Table 2 is a bulk value calculated from . The maximum relative error associated with this approximation is equal to the nondimensional parameter . For the current experiment this is ≈0.42, which is comparable to similar experiments in the literature. Table 2. List of experiments. It has been noted ( Ohlsen and Rhines 1997 ; Read 2005 ) that the topographic β effect can only be felt by a density-stratified fluid near the sloping boundaries. However, the

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