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Felipe M. Pimenta, A. D. Kirwan Jr., and Pablo Huq

more dense, quiescent lower layer of density ρ a ( Fig. 1b ). For this configuration, the transport is given by T = g ′ p h 2 /2 f , where h is the plume depth and g ′ p = g ( ρ a − ρ p )/ ρ a the reduced gravity. This frontal model has been extensively used in the development of theories and the scaling analysis of laboratory and numerical results ( Garvine 1999 ; Lentz and Helfrich 2002 ; Fong and Geyer 2002 ). Other studies have considered the transport of stratified fronts in the

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Ryan Abernathey and George Haller

fluxes (i.e., statistical correlations between velocity and tracer fluctuations, also known as Reynolds fluxes) play a significant role in the transport of heat, salt, momentum, and other tracers through the ocean. Because climate models generally do not resolve the mesoscale, the subgrid-scale mesoscale flux must be parameterized based on the large-scale flow properties, commonly using a diffusive closure ( Gent et al. 1995 ; Treguier et al. 1997 ; Visbeck et al. 1997 ; Vollmer and Eden 2013

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K. H. Brink and S. J. Lentz

1. Introduction In a stratified ocean, cross-isobath Ekman transport (associated with an along-isobath flow) causes vertical motions and therefore contributes to the development of a horizontal density gradient. In the initial stages of adjustment, turbulent mixing and dissipation are important; however, with time, a nonturbulent equilibrium can be established. Regardless of the upslope or downslope sense of the Ekman transport, the horizontal density gradient acts, through thermal wind balance

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Michael A. Spall, Robert S. Pickart, Paula S. Fratantoni, and Albert J. Plueddemann

distinct water masses, perhaps related to the winter and summer water masses on the Chukchi shelf ( Pickart et al. 2005 ). The heat and salt transported seaward by the most commonly observed eddies are believed to be fundamental to the ventilation of the interior Arctic halocline (e.g., Muench et al. 2000 ). These eddies also represent a source of nutrients and zooplankton to the central basin ( Llinas et al. 2008 ), and are potentially important for the off-shelf flux of organic carbon ( Mathis et al

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J. N. Moum, J. M. Klymak, J. D. Nash, A. Perlin, and W. D. Smyth

evident. At 20 km offshore a large-wavelength wave is seen propagating onshore at about 0.3 m s −1 ; the leading edge of this wave appears to be borelike. A train of smaller-scale waves inshore at 1.5 km is aliased in our profiling observations. In both cases, the influence of the waves is clear throughout the water column. In winter, the water column is typically weakly stratified, from the combination of wind-driven mixing, onshore transport of light near-surface fluid in the upper Ekman layer, and

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Noboru Nakamura

1. Introduction Large-scale transport and mixing has a profound impact on the global distribution and chemistry of trace constituents in the atmosphere. In the upper troposphere and lower stratosphere (UTLS), a combination of large-scale, quasi-isentropic stirring and the eddy-driven meridional overturning ( Brewer 1949 ; Dobson 1956 ) is the main driver of global transport ( Plumb 2002 ; Haynes 2005 ; Shepherd 2007 ). Climate models represent these processes reasonably well, but the

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Juan M. Restrepo and Jorge M. Ramirez

1. Introduction The mean transport due to progressive waves here refers to the mean Lagrangian velocity generated by the waves. Longuet-Higgins (1953) presented a derivation of the mean Lagrangian transport, due to monochromatic waves, as an asymptotic series of averaged parcel paths and related the terms in the Lagrangian series to a series in the Eulerian framework. The asymptotic parameter was identified as the small distance traveled by a fluid parcel over a period of the wave motion. The

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Paolo Ruggieri, M. Carmen Alvarez-Castro, Panos Athanasiadis, Alessio Bellucci, Stefano Materia, and Silvio Gualdi

1. Introduction The transport of heat is a fundamental phenomenon in planetary oceans and atmospheres. Transfer of heat from low to high latitudes has an intimate connection with nonuniform insolation, but its partitioning and variability stimulated decades of research and efforts to understand a surprisingly complex phenomenon. Outside of the tropics, a large fraction of heat transport is undertaken by the atmosphere ( Czaja and Marshall 2006 ; Trenberth and Caron 2001 ). Atmospheric heat

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Jacob O. Wenegrat and Leif N. Thomas

1. Introduction The classic Ekman balance can be understood in terms of vorticity dynamics as a balance between the turbulent diffusion of horizontal vorticity and the tilting of vertical planetary vorticity ( Thomas and Rhines 2002 ). This balance leads to a horizontal mass transport with a magnitude that is simply the ratio of the surface wind stress and the Coriolis frequency, a powerful framework for understanding the influence of surface forcing on the ocean ( Ekman 1905 ). Beyond the

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Paul Konopka, Felix Ploeger, Mengchu Tao, and Martin Riese

1. Introduction Although tropospheric air enters the stratosphere predominantly through the tropical tropopause layer (TTL) ( Fueglistaler et al. 2009 ), there is a wide range of pathways connecting the planetary boundary layer (PBL) with the TTL itself (e.g., Levine et al. 2007 ; Randel et al. 2010 ; Vogel et al. 2011 ). Different diagnostics have been developed to quantify such pathways. The age spectrum of air has been shown to be a comprehensive diagnostic of atmospheric transport

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