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Allan J. Clarke and Anna Lebedev

and longer variations have been occurring throughout this century. This climate signal differs markedly from the slow monotonic rise we might expect from purely anthropogenic effects. Basically, the climate signal seems to be “natural.” 3. Mechanisms for long-term coastal change a. Local California coastal winds What drives such long-timescale changes in California coastal waters? One explanation might be that the coastal southward alongshore winds, which can drive coastal upwelling, gradually

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Dan E. Kelley and Kim A. Van Scoy

1. Introduction Accounting for the effects of vertical mixing in large-scale ocean models requires parameterization because the spatial and temporal scales of mixing are too small to resolve directly. A common parameterization employs a nonisotropic analogy to molecular diffusion, with the diffusivity being divided into components, K H and K V , representing downgradient fluxes along and across geopotential surfaces, respectively. Here we focus on vertical mixing in the upper pycnocline of

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S. L. Gray and T. W. N. Haine

attempt to combine observations with a model circulation has shown the model circulation to be marginally inconsistent with the CFC observations, prior flux estimates, and the estimated errors in these quantities when the effects of unresolved variability are considered; that is, the inverse almost satisfies the null hypothesis, ℋ 0 . This can be compared with recent work by Heinze et al. (1998) , who concluded that CFCs, anthropogenic tritium, and tritiugenic helium-3 are inconsistent with a 3

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Paul E. Robbins, James F. Price, W. Brechner Owens, and William J. Jenkins

both analytic ( Luyten et al. 1983, hereafter LPS ) and numeric ( Bleck et al. 1992 ; New et al. 1995 ) models of ocean circulation. Measurements of anthropogenically produced tracers in the ocean ( Rooth and Östlund 1972 ; Jenkins 1980 ; Fine et al. 1981 ; Sarmiento et al. 1982 ; Fine et al. 1987 ) support the hypothesis that the transmission of the surface properties into the interior thermocline is largely confined to transport along isopycnal surfaces and that diapycnal effects are second

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Akio Ishida, Yoshikazu Sasai, and Yasuhiro Yamanaka

1. Introduction The transport of anthropogenic gases in the ocean is one of the key processes for understanding and predicting future atmospheric and oceanic climate, as the uptake and penetration of anthropogenic carbon dioxide (CO 2 ) is closely related to these transport processes. Chlorofluorocarbons (CFCs) are ideal tracers for investigating ocean circulation over decadal to interdecadal time scales because CFCs are inert transient tracers whose solubility properties, atmospheric history

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Timothy M. Hall, Thomas W. N. Haine, Darryn W. Waugh, Mark Holzer, Francesca Terenzi, and Deborah A. LeBel

6 m 3 s −1 ) for Labrador Sea Water (LSW), Rhein et al. (2002) estimated a formation rate of 4.4–5.6 Sv for LSW, and Orsi et al. (1999) estimated the formation rate of 12 Sv for Antarctic Bottom Water (AABW). Details of these analyses differ, and the investigators have estimated sensitivities to several assumptions. Smethie and Fine (2001) and Rhein et al. (2002) estimate the effects of variable transport, obtaining wide differences in formation rates in years of weak and strong LSW

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Synte Peacock and Mathew Maltrud

potentially be of great value in efforts to predict ocean uptake and redistribution of chemical tracers and pollutants. One of the most promising applications of the TTD is to improve estimates of anthropogenic CO 2 uptake by the ocean. Most current estimates of anthropogenic CO 2 uptake are based on the assumption that the flow is dominated by advection, and that a chlorofluorocarbon (CFC)-derived age characterizes the mean transit time ( Gruber et al. 1996 ; McNeil et al. 2003 ). However, Hall et al

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W. J. Jenkins

theSargasso Sea, and the tr/tium-heliura age equation, the isopycnal eddy diffus/vity is estimated to be 1840 :t: 440ma s-~ within the main thermocline. The penetration of anthropogenic substances intothe ocean provides us with the opportunity to determine the rates of processes responsible for ocean ventilation. While observations of the evolution of transient tracer distributions can in principle yield quantitative estimates of ocean mixing and circulation, weare hampered by imperfect knowledge of

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Katherine A. Adams, Philip Hosegood, John R. Taylor, Jean-Baptiste Sallée, Scott Bachman, Ricardo Torres, and Megan Stamper

.70 m are updated values from Sallée et al. (2008) . North of the SAF, water masses such as Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW) subduct along isopycnals at specific locations in the Southern Ocean, such as the Scotia Sea ( Sallée et al. 2010 ). The subducted pools of SAMW and AAIW observed north of the ACC contain high levels of anthropogenic CO 2 ( Sabine et al. 2004 ; Pardo et al. 2014 ) and heat ( Frölicher et al. 2015 ). Currently, SAMW is thought to be

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S. D. Bachman, J. R. Taylor, K. A. Adams, and P. J. Hosegood

mixed layer depth and vertical velocity The effects of downscaling from mesoscale-permitting to submesoscale-permitting resolution have been explored in previous studies comparing model dynamics at multiple scales (e.g., Capet et al. 2008a , b , c ; Rosso et al. 2014 , 2015 , 2016 ), which is most readily seen in the appearance of MLE. MLE are energized by converting potential energy into kinetic energy and in doing so tilt density surfaces toward the horizontal and increase the mixed layer

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