Abstract
One of the most striking features of the upper North Atlantic Ocean is an extensive layer of water with temperature close to 18°C and salinity close to 36.5‰, (ref. 1). This 18°C water is formed by winter convection in the Sargasso sea2,3, but aspects of the annual rate of 18°C water formation remain obscure4. We have simulated this water mass formation by integrating a one-dimensional model along a 4-yr trajectory of a water column circulating around the Sargasso Sea. Winter convection is deep (≥200 m) in regions where the ocean suffers a net annual heat loss to the atmosphere, and shallow (≤lOOm) where the ocean gains heat each year. The origin of the thermostad (nearly isothermal layer) is a thick layer of nearly homogeneous water subducted beneath the seasonal boundary layer in the year that the water column passes through the line dividing annual cooling from annual heating. We estimate the annual production of 18°C water to be 446,000 km3 yr−1. Downstream, more stratified central water is formed each year at a rate that depends more on Ekman pumping (wind-forced convergence) than on the decreasing depth of winter convection.
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References
Worthington, L. V. in Evolution of Physical Oceanography (eds Warren, B. A. & Wunsch, C.) 42–69 (MIT Press, Cambridge, 1981).
Worthington, L. V. Deep-Sea Res. 5, 297–305 (1959).
Istoshin Yu, V. Deep-Sea Res. 7, 384–390 (1962).
Worthington, L. V. Johns Hopkins Oceanogr. Stud. 6, (1976).
Wyville Thomson, C. The Voyage of the Challenger. The Atlantic, (Mcmillan, London, 1877).
Wyville Thomson, C. & Murray, J. (eds) Challenger Report Part 2 Vol. 1 (HMSO, London, 1884).
McCartney, M. S. Deep-Sea Res. (Suppl.) 24, 103–119 (1977).
McCartney, M. S. J. mar. Res. (Suppl.) 40, 427–464 (1982).
McCartney, M. S. & Talley, L. D. J. phys. Oceanogr. 12, 1169–1188 (1982).
Talley, L. D. & McCartney, M. S. J. phys. Oceanogr. 12, 1189–1205 (1982).
Masuzawa, J. Deep-Sea Res. 16, 463–472 (1969).
Bryan, K. & Manabe, S. in Coupled Ocean-Atmosphere Models (ed. Nihoul, J. C. J.) 1–6 (Elsevier, Amsterdam, 1985).
Woods, J. D., Barkmann, W. & Strass, V. in The Ocean Surface: Wave Breaking, Turbulent Mixing and Radio Probing (eds Toba, Y. & Mitsuyasu, H.) 487–507 (Reidel, Dordrecht, 1985).
McCartney, M. S., Worthington, L. V. & Raymer, M. E. J. mar. Res. 38, 147–172 (1980).
Worthington, L. V. in Studies in Physical Oceanography (ed. Gordon, A. L.) 169–178 (Gordon and Breach, New York, 1971).
Schroeder, E., Stommel, H., Menzel, D. & Sutcliffe, W. J. geophys. Res. 64, 363–366 (1959).
Jenkins, W. J. J. mar. Res. (Suppl.) 40, 267–290 (1982).
Talley, L. D. & Raymer, M. E. J. mar. Res. Suppl, 40, 757–775 (1982).
Pollard, R. T. & Pu, S. Prog. Oceanogr. 14, 443–462 (1985).
Woods, J. D. Nature 314, 501–511 (1985).
Woods, J. D. in Coupled Ocean-Atmosphere Models (ed. Nihoul, J. C. J.) 543–590 (Elsevier, Amsterdam, 1985).
Bryan, K. & Lewis, L. J. J. geophys. Res. 84, 2503–2517 (1979).
Gates, W. L., Han, Y.-J. & Schlesinger, M. in Coupled Ocean-Atmosphere Models (ed. Nihoul, J. C. J.) 131–152 (Elsevier, Amsterdam, 1985).
Woods, J. D. & Barkmann, W. Q. J. R. met. Soc. 112, 1–27 (1986).
Davis, R. E., DeSzoeke, R. & Niiler, P. Deep-Sea Res. 28, 1453–1476 (1981).
Sarmiento, J. J. phys. Oceanogr. 13, 1924–1939 (1983).
Stommel, H. Proc. natn. Acad. Sci. U.S.A. 76, 2518–2521 (1979).
Stommel, H. Proc. natn. Acad. Sci. U.S.A. 76, 3051–3055 (1979).
Sarmiento, J. J. phys. Oceanogr. 13, 1269–1274 (1983).
Isemer, H. J. & Hasse, L. The Bunker Climate Atlas of the Atlantic Ocean (Springer, Berlin, 1985).
Baumgartner, A. & Reichel, E. The World Water Balance (Elsevier, Amsterdam, 1975).
Robinson, M. K., Bauer, R. A. & Schroeder, E. H. Atlas of North Atlantic-Indian Ocean Monthly Mean Temperatures and Mean Salinities of the Surface Layer (US Naval Ocanographie Office Ref. Publ. 18, Washington DC, 1979).
Worthington, L. V. J. phys. Oceanogr. 2, 205–211 (1972).
Jenkins, W. J. mar. Res. 38, 533–569 (1980).
Sarmiento, J. L., Rooth, C. G. H. & Roether, W. J. geophys. Res. 87, 8047–8056 (1982).
Stommel, H. & Schott, F. Deep-Sea Res. 24, 325–329 (1977).
Woods, J. D. in The Global Climate (ed. Houghton, J. T.) 141–187 (Cambridge University Press, 1984).
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Woods, J., Barkmann, W. A lagrangian mixed layer model of Atlantic 18°C water formation. Nature 319, 574–576 (1986). https://doi.org/10.1038/319574a0
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DOI: https://doi.org/10.1038/319574a0
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