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

1. Introduction and motivation The general circulation of the ocean is forced by surface fluxes of momentum, heat, and freshwater at basin scales. A large fraction of the kinetic energy E k associated with the large-scale forcing must be dissipated at molecular scales in order for the circulation to remain approximately steady. The E k pathways across this wide range of scales remain poorly understood ( Ferrari and Wunsch 2009 ). Possible routes to dissipation include nonlinear internal

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Michael A. Spall

in the upper right corner of the figure. To the south of y = 350 km, the model temperature and salinity are restored toward 6°C and 35, respectively. The ocean circulation model is coupled to an ice model with thermodynamics that simulate ice thickness and concentration, based on the two-category model of Hibler (1980) . The albedo reflects that of wet (0.66) or dry (0.75) ice, depending on if there is sufficient heat flux to form melt pools. The two-category ice model uses a so-called zero

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

energy of fronts is stored in horizontal density gradients, from which energy may be extracted through slumping by eddies into vertical gradients. As a result of this slumping, a positive submesoscale vertical temperature flux is created since warmer water is transported toward the surface and cooler water is transported to greater depths, thereby reinforcing vertical stratification ( Boccaletti et al. 2007 ; Fox-Kemper et al. 2008 ). It has long been known that turbulent processes at even smaller

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Ryan Abernathey and Paola Cessi

Fig. 1 we plot the vertically integrated divergence of the transient eddy heat flux in the ACC region, as calculated from the eddy-permitting Southern Ocean State Estimate (SOSE; Mazloff et al. 2010 ). We also plot the net mean (i.e., time averaged) and eddy (i.e., the departure from time average) heat transports across the ACC streamlines. (See section 2 for further details of the calculation.) The figure clearly illustrates that the eddy fluxes are an order of magnitude larger in the

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R. M. Holmes and L. N. Thomas

alternating warm and cold phases. TIWs and their associated vortices [tropical instability vortices (TIVs)] drive lateral heat fluxes that warm the cold tongue by ~1°C month −1 ( Menkes et al. 2006 ; Jochum et al. 2007 ; Graham 2014 ), potentially contributing to the asymmetry of the ENSO cycle ( An 2008 ; Imada and Kimoto 2012 ). Jochum and Murtugudde (2006) suggested that TIWs warm the cold tongue not through typical eddy mixing, but instead through modifications of the air–sea fluxes and vertical

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Vamsi K. Chalamalla and Sutanu Sarkar

continuously increases during the evolution from a very small value to an O (1) value. The flux coefficient Γ i = B i / ε , where B i is the irreversible buoyancy flux, was found to decrease with increasing time or, equivalently, with increasing value of L O / L T . More recently, Mater et al. (2013) examined the relationship between L T and L O using three-dimensional DNS results of decaying, statistically homogeneous, stratified turbulence. It was found that L T and L O were not linearly

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Nicolas Grisouard and Leif N. Thomas

frequency f , or inertial waves, propagating in oceanic fronts can flux energy either horizontally, as in the classical limit, or on a slanted path. In Grisouard and Thomas (2015 , hereinafter referred to as GT15) , we studied a consequence of this property, which is that when waves of frequency f propagate upward (e.g., associated with a formerly superinertial wave that has propagated from a lower latitude; see section 7 in GT15 for additional examples) along the steep angle and encounter the

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

1. Introduction In the Southern Ocean, the air–sea buoyancy flux acts together with the wind stress to create the Antarctic Circumpolar Current (ACC). This current flows essentially in geostrophic balance with the meridional density gradient set by the freezing temperatures near Antarctica and the warm subtropical gyres. The ACC is not a single front but a complex system of fronts, several of which are thought to be of circumpolar extent ( Orsi et al. 1995 ). Two principal fronts typically

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

vertical internal-wave energy fluxes, bottom generation of internal waves was found to be negligible in all of the simulations. Vertical diffusivities are 10 −5 m 2 s −1 everywhere. No hyperviscosities or hyperdiffusivities are used. To provide realistic initial conditions for the modeled Kuroshio, the 2008 grid-averaged meridional density section ( Nagai et al. 2009 ) is used. To suppress initial unbalanced disturbances in the simulation, temperature and salinity at each vertical level across the

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Juan A. Saenz, Rémi Tailleux, Edward D. Butler, Graham O. Hughes, and Kevin I. C. Oliver

reveal the role and importance of surface buoyancy fluxes and interior mixing processes of heat and salt in forcing and dissipating the ocean circulation. These processes control, at least in part, the sign and magnitude of the net conversion between potential and kinetic energy in the oceans. Linking the mechanical energy (gravitational potential plus kinetic energy) budget to surface buoyancy fluxes and interior mixing processes has been a controversial topic and has been overlooked in recent

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