• Boebel, O., R. E. Davis, M. Ollitrault, R. G. Peterson, P. L. Richardson, C. Schmid, and W. Zenk, 1999: The intermediate depth circulation in the western South Atlantic. Geophys. Res. Lett., 26 ((21),) 33293332.

    • Search Google Scholar
    • Export Citation
  • Böning, C., and P. Herrmann, 1994: Annual cycle of poleward heat transport in the ocean: Results from high-resolution modeling of the north and equatorial Atlantic. J. Phys. Oceanogr., 24 , 91107.

    • Search Google Scholar
    • Export Citation
  • Broecker, W. S., and T-H. Peng, 1982: Tracers in the Sea. Lamont-Doherty Geological Observatory, Columbia University, 690 pp.

  • Bullister, J. L., 1989: Chlorofluorocarbons as time-dependent tracers in the ocean. Oceanography, 2 , 1217.

  • Coachman, L. K., and K. Aagaard, 1988: Transports through Bering Strait: Annual and interannual variability. J. Geophys. Res., 93 ((C12),) 1553515539.

    • Search Google Scholar
    • Export Citation
  • daSilva, A. M., C. C. Young, and S. Levitus, 1994: Algorithms and Procedures. Vol. 1, Atlas of Surface Marine Data 1994, NOAA Atlas NESDIS 6, 83 pp.

    • Search Google Scholar
    • Export Citation
  • Defant, A., 1941: Quantitative Untersuchungen zur Statik und Dynamik des Atlantischen Ozeans. Wiss. Ergebn. Dt. Atl. Exp. “METEOR” 1925–1927, 6 ((2),) 191260.

    • Search Google Scholar
    • Export Citation
  • De Madron, X. D., and G. Weatherly, 1994: Circulation, transport and bottom boundary layers of deep currents in the Brazil Basin. J. Mar. Res., 52 , 583638.

    • Search Google Scholar
    • Export Citation
  • Dickson, R. R., and J. Brown, 1994: The production of North Atlantic Deep Water: Sources, rates and pathways. J. Geophys. Res., 99 ((C6),) 1231912341.

    • Search Google Scholar
    • Export Citation
  • England, M. H., and V. C. Garçon, 1994: South Atlantic circulation in a World Ocean model. Ann. Geophys., 12 , 812825.

  • Fine, R. A., and R. L. Molinari, 1988: A continuous deep western boundary current between Abaco (26.5°N) and Barbados (13°N). Deep-Sea Res., 35A , 14411450.

    • Search Google Scholar
    • Export Citation
  • Fofonoff, N. P., 1985: Physical properties of seawater: A new salinity scale and equation of state of seawater. J. Geophys. Res., 90 ((C2),) 33323342.

    • Search Google Scholar
    • Export Citation
  • Friedrichs, M. A. M., M. S. McCartney, and M. M. Hall, 1994: Hemispheric asymmetry of deep water transport modes in the western Atlantic. J. Geophys. Res., 99 ((C12),) 2516525179.

    • Search Google Scholar
    • Export Citation
  • Fuglister, F. C., 1960: Atlantic Ocean Atlas of Temperature and Salinity Profiles and Data from the International Geophysical Year of 1957–1958. Woods Hole Oceanographic Institution Atlas Series, Vol. 1, WHOI, 209 pp.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., 1999: Large scale oceanic circulation and fluxes of freshwater, heat, nutrients and oxygen. Ph.D. thesis, Massachusetts Institute of Technology–Woods Hole Oceanographic Institute Joint Program, 266 pp.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., and C. Wunsch, 2000: Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408 , (6811),. 453457.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., J. Marotzke, and J. Toole, 2000: Meridional overturning and large-scale circulation of the Indian Ocean. J. Geophys. Res., 105 ((C11)) 2611726134.

    • Search Google Scholar
    • Export Citation
  • Garzoli, S. L., G. J. Goñi, A. J. Mariano, and D. B. Olson, 1997: Monitoring the upper southeastern Atlantic transports using altimeter data. J. Mar. Res., 55 ((3),) 453481.

    • Search Google Scholar
    • Export Citation
  • Gordon, A. L., 1986: Interocean exchange of thermocline water. J. Geophys. Res., 91 ((C4),) 50375046.

  • Hall, M. M., and H. L. Bryden, 1982: Direct estimates and mechanisms of ocean heat transport. Deep-Sea Res., 29 , (3A),. 339359.

  • Hall, M. M., M. S. McCartney, and J. A. Whitehead, 1997: Antarctic Bottom Water flux in the equatorial western Atlantic. J. Phys. Oceanogr., 27 , 19031926.

    • Search Google Scholar
    • Export Citation
  • Hellerman, S., and M. Rosenstein, 1983: Normal monthly wind stress over the World Ocean with error estimates. J. Phys. Oceanogr., 13 , 10931104.

    • Search Google Scholar
    • Export Citation
  • Hogg, N. G., 2001: Quantification of the deep circulation. Ocean Circulation and Climate—Observing and Modelling the Global Ocean, G. Siedler, J. Church, and J. Gould, Eds., International Geophysics Series, Vol. 77, Academic Press, 259–270.

    • Search Google Scholar
    • Export Citation
  • Hogg, N. G., and W. B. Owens, 1999: Direct measurement of the deep circulation within the Brazil Basin. Deep-Sea Res. II, 46 , 335353.

    • Search Google Scholar
    • Export Citation
  • Hogg, N. G., G. Siedler, and W. Zenk, 1999: Circulation and variability at the southern boundary of the Brazil Basin. J. Phys. Oceanogr., 29 , 145157.

    • Search Google Scholar
    • Export Citation
  • Holfort, J., and G. Siedler, 2001: The meridional oceanic transports of heat and nutrients in the South Atlantic. J. Phys. Oceanogr., 31 , 529.

    • Search Google Scholar
    • Export Citation
  • Holfort, J., K. M. Johnson, B. Schneider, G. Siedler, and D. W. R. Wallace, 1998: Meridional transports of dissolved inorganic carbon in the South Atlantic Ocean. Global Biochem. Cycles, 12 , 479499.

    • Search Google Scholar
    • Export Citation
  • Jackett, D., and T. McDougall, 1997: A neutral density variable for the world's oceans. J. Phys. Oceanogr., 27 , 237263.

  • Larqué, L., K. Maamaatuaiahutapu, and V. Garçon, 1997: On the intermediate and deep water flows in the South Atlantic Ocean. J. Geophys. Res., 102 , 1242512440.

    • Search Google Scholar
    • Export Citation
  • Ledwell, J. R., E. T. Montgomery, K. L. Polzin, L. C. St. Laurent, R. W. Schmitt, and J. M. Toole, 1999: Evidence for enhanced mixing over rough topography in the abyssal ocean. Nature, 403 , 179182.

    • Search Google Scholar
    • Export Citation
  • Ledwell, J. R., T. Donoghue, B. Guest, P. Lemmond, C. Sellers, and N. Cortes, 2000: Brazil Basin Tracer Release Experiment. WHOI Cruise Rep. R/V Knorr Cruise 161-6, 39 pp.

    • Search Google Scholar
    • Export Citation
  • Lovelock, J. E., R. J. Maggs, and R. J. Wade, 1973: Halogenated hydrocarbons in and over the Atlantic. Nature, 241 , 194196.

  • Lux, M., H. Mercier, and M. Arhan, 2001: Interhemispheric exchanges of mass and heat in the Atlantic Ocean in January–March 1993. Deep-Sea Res. I, 48 , 605638.

    • Search Google Scholar
    • Export Citation
  • Macdonald, A. M., 1993: Property fluxes at 30°S and their implications for the Pacific–Indian throughflow and the global heat budget. J. Geophys. Res., 98 ((C4),) 68516868.

    • Search Google Scholar
    • Export Citation
  • Macdonald, A. M., . 1998: The global ocean circulation: A hydrographic estimate and regional analysis. Progress in Oceanography, Vol. 41, Pergamon, 281–382.

    • Search Google Scholar
    • Export Citation
  • Macdonald, A. M., and C. Wunsch, 1996: An estimate of global ocean circulation and heat fluxes. Nature, 382 , 436439.

  • Marin, F., and Y. Gouriou, 2000: Heat fluxes across 7°30 N and 4°30 S in the Atlantic Ocean. Deep-Sea Res. I, 47 , 21112139.

  • McCartney, M. S., 1993: Crossing of the equator by the deep western boundary current in the western Atlantic Ocean. J. Phys. Oceanogr., 23 , 19531974.

    • Search Google Scholar
    • Export Citation
  • Mémery, L., M. Arhan, X. A. Alvarez-Salgado, J. Messias, H. Mercier, C. G. Castro, and A. F. Rios, 2000: The water masses along the western boundary of the South and equatorial Atlantic. Progress in Oceanography, Vol. 47, Pergamon, 69–98.

    • Search Google Scholar
    • Export Citation
  • Mercier, H., and M. Arhan, 1997: Two meridional hydrographic sections in the eastern South Atlantic Ocean (WHP lines A13 and A14). Int. WOCE Newslett., 28 , 2830.

    • Search Google Scholar
    • Export Citation
  • Mercier, H., and P. Morin, 1997: Hydrography of the Romanche and Chain Fracture Zone. J. Geophys. Res., 102 , 1037310389.

  • Mercier, H., G. L. Weatherly, and M. Arhan, 2000: Bottom water throughflows at the Rio de Janeiro and Rio Grande Fracture Zones. Geophys. Res. Lett., 27 , 15031506.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., G. C. Johnson, and J. L. Bullister, 1999: Circulation, mixing, and production of Antarctic Bottom Water. Progress in Oceanography, Vol. 43, Pergamon, 55–109.

    • Search Google Scholar
    • Export Citation
  • Peterson, R. G., and T. I. Whitworth, 1989: The subantarctic and polar fronts in relation to deep water masses through the southwestern Atlantic. J. Geophys. Res., 94 ((C8),) 1081710838.

    • Search Google Scholar
    • Export Citation
  • Pickart, R. S., 1992: Water mass components of the North Atlantic deep western boundary current. Deep-Sea Res., 39 , 15531572.

  • Pickart, R. S., N. G. Hogg, and W. M. Smethie Jr., 1989: Determining the strength of the deep western boundary current using the chlorofluoromethane ratio. J. Phys. Oceanogr., 19 , 940951.

    • Search Google Scholar
    • Export Citation
  • Polzin, K. L., J. M. Toole, J. R. Ledwell, and R. W. Schmitt, 1997: Spatial variability of turbulent mixing in the abyssal ocean. Science, 276 , 9396.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 1989: On the total geostrophic circulation of the South Atlantic Ocean: Flow patterns, tracers and transports. Progress in Oceanography, Vol. 23, Pergamon, 149–244.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., W. D. Nowlin Jr., and W. C. Patzert, 1977: On the characteristics and circulation of the southwestern Atlantic Ocean. J. Phys. Oceanogr., 7 , 6291.

    • Search Google Scholar
    • Export Citation
  • Rhein, M., 1994: The deep western boundary current: Tracers and velocities. Deep-Sea Res., 41 , 263281.

  • Rhein, M., L. Stramma, and U. Send, 1995: The Atlantic Deep Western Boundary Current: Water masses and transports near the equator. J. Geophys. Res., 100 ((C2),) 24412457.

    • Search Google Scholar
    • Export Citation
  • Rhein, M., and G. Krahmann, 1998: The spreading of Antarctic Bottom Water in the tropical Atlantic. Deep-Sea Res. I, 45 , 507527.

  • Rintoul, S. R., 1991: South Atlantic interbasin exchange. J. Geophys. Res., 96 ((C2),) 26752692.

  • Robbins, P. E., and J. M. Toole, 1997: The dissolved silica budget as a constraint on the meridional overturning circulation of the Indian Ocean. Deep-Sea Res. I, 44 , 879906.

    • Search Google Scholar
    • Export Citation
  • Roether, W., and A. Putzka, 1996: Transient-tracer information on ventilation and transport of South Atlantic waters. The South Atlantic: Present and Past Circulation, G. Wefer et al., Eds., Springer Verlag, 83–104.

    • Search Google Scholar
    • Export Citation
  • Roether, W., R. Well, A. Putzka, and C. Rüth, 1998: Component separation of oceanic helium. J. Geophys. Res., 103 ((C12),) 2793127946.

    • Search Google Scholar
    • Export Citation
  • Rüth, C., 1998: Heliumisotopen- und Neon-Messungen im Südatlantik: Ozeanographische und geochemische Anwendungen. Ph.D. thesis, Institut für Umweltphysik, Universität Bremen, 117 pp.

    • Search Google Scholar
    • Export Citation
  • Rüth, C., R. Well, and W. Roether, 2000: Primordial 3 He in South Atlantic deep waters from sources on the mid-Atlantic ridge. Deep-Sea Res., 47 , 10591075.

    • Search Google Scholar
    • Export Citation
  • Saunders, P. M., and B. A. King, 1995: Oceanic fluxes on the WOCE A11 section. J. Phys. Oceanogr., 25 , 19421958.

  • Schmid, C., G. Siedler, and W. Zenk, 2000: Dynamics of intermediate water circulation in the subtropical South Atlantic. J. Phys. Oceanogr., 30 , 31913211.

    • Search Google Scholar
    • Export Citation
  • Schmitz, W. J., 1995: On the interbasin scale thermohaline circulation. Rev. Geophys., 33 , 151173.

  • Schmitz, W. J., . 1996a: On the World Ocean circulation: Vol. I, Some global features/North Atlantic circulation. WHOI Tech. Rep. WHOI-96-03, 141 pp.

    • Search Google Scholar
    • Export Citation
  • Schmitz, W. J., . 1996b: On the World Ocean circulation: Vol. II, The Pacific and Indian Oceans/A global update,. WHOI Tech. Rep. WHOI-96-08, 237 pp.

    • Search Google Scholar
    • Export Citation
  • Servain, J., and S. Lukas, 1990: Climatic atlas of the Tropical Atlantic Wind Stress and Sea Surface Temperature 1985–1989. IFREMER, 133 pp.

    • Search Google Scholar
    • Export Citation
  • Servain, J., F. Gohin, and A. Muzellec, 1993: Wind fields at the sea surface determined from combined ship and satellite altimeter data. J. Atmos. Oceanic Technol., 10 , 880886.

    • Search Google Scholar
    • Export Citation
  • Smith, W. H. F., and D. T. Sandwell, 1997: Global seafloor topography from satellite altimetry and ship depth soundings. Science, 277 , 19561962.

    • Search Google Scholar
    • Export Citation
  • Speer, K. G., and W. Zenk, 1993: The flow of Antarctic Bottom Water into the Brazil Basin. J. Phys. Oceanogr., 23 , 26672682.

  • Speer, K. G., G. Siedler, and L. D. Talley, 1995: The Namib Col Current. Deep-Sea Res. I, 42 , 19331950.

  • Speer, K. G., J. Holfort, T. Reynaud, and G. Siedler, 1996: South Atlantic heat transport at 11°S. The South Atlantic: Present and Past Circulation, G. Wefer et al., Eds., Springer Verlag, 105–120.

    • Search Google Scholar
    • Export Citation
  • Stammer, D., R. Tokmakian, A. Semtner, and C. Wunsch, 1996: How well does a ¼° global circulation model simulate large-scale oceanic observations? J. Geophys. Res., 101 ((C11),) 2577925811.

    • Search Google Scholar
    • Export Citation
  • Stramma, L., 1991: Geostrophic transport of the South Equatorial Current in the Atlantic. J. Mar. Res., 49 , 281294.

  • Stramma, L., and M. England, 1999: On the water masses and mean circulation of the South Atlantic Ocean. J. Geophys. Res., 104 ((C9),) 2086320883.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., 1996: Antarctic Intermediate Water in the South Atlantic. The South Atlantic: Present and Past Circulation, G. Wefer et al., Springer Verlag, 219–238.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., and C. Johnson, 1994: Deep, zonal subequatorial currents. Science, 263 , 11251128.

  • Treguier, A-M., N. G. Hogg, M. E. Maltrud, K. G. Speer, and V. Thierry, 2002: On the origin of the deep zonal flows in the Brazil Basin. J. Phys. Oceanogr., in press.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., J. G. Olson, and W. G. Large, 1989: A global ocean wind stress climatology based on ECMWF analyses. NCAR Tech. Note 338+STR, 93 pp.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., W. G. Large, and J. G. Olson, 1990: The mean annual cycle in global ocean wind stress. J. Phys. Oceanogr., 20 , 17421760.

    • Search Google Scholar
    • Export Citation
  • Tsuchiya, M., L. D. Talley, and M. S. McCartney, 1994: Water-mass distributions in the western South Atlantic; a section from South Georgia Island (54S) northward across the equator. J. Mar. Res., 52 , 5581.

    • Search Google Scholar
    • Export Citation
  • Warren, B. A., and K. G. Speer, 1991: Deep circulation in the eastern South Atlantic Ocean. Deep-Sea Res., 38 , (Suppl.),. 281322.

  • Weatherly, G. L., Y. Y. Kim, and E. A. Kontar, 2000: Eulerian measurements of the North Atlantic Deep Water Deep Western Boundary Current at 18°S. J. Phys. Oceanogr., 30 , 971986.

    • Search Google Scholar
    • Export Citation
  • Weiss, R. F., J. L. Bullister, R. H. Gammon, and M. J. Warner, 1985: Atmospheric chloroflouromethanes in the deep equatorial Atlantic. Nature, 314 , 608610.

    • Search Google Scholar
    • Export Citation
  • Wienders, N., M. Arhan, and H. Mercier, 2000: Circulation at the western boundary of the South and Equatorial Atlantic: Exchanges with the ocean interior. J. Mar. Res., 58 , 10071039.

    • Search Google Scholar
    • Export Citation
  • Wunsch, C., 1978: The North Atlantic general circulation west of 5°W determined by inverse methods. Rev. Geophys. Space Phys., 16 , 583620.

    • Search Google Scholar
    • Export Citation
  • Wüst, G., 1935: Schichtung und Zirkulation des Atlantischen ozeans. Das bodenwasser und die stratosphäre. Wiss. Ergebn. Dt. Atl. Exp. “METEOR” 1925–1927, 6 , 1288.

    • Search Google Scholar
    • Export Citation
  • You, Y., 1999: Dianeutral mixing, transformation and transport of Antarctic Intermediate Water in the South Atlantic Ocean. Deep-Sea Res. II., 46 , 393435.

    • Search Google Scholar
    • Export Citation
  • Zangenberg, N., and G. Siedler, 1998: The path of the North Atlantic Deep Water in the Brazil Basin. J. Geophys. Res., 103 , 54195428.

    • Search Google Scholar
    • Export Citation
  • Zenk, W., G. Siedler, B. Lenz, and N. G. Hogg, 1999: Antarctic Bottom Water flow through the Hunter Channel. J. Phys. Oceanogr., 29 , 27852801.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 244 34 3
PDF Downloads 80 28 1

Zonal Fluxes in the Deep Water Layers of the Western South Atlantic Ocean

Michal VanicekInstitut für Meereskunde, Kiel, Germany

Search for other papers by Michal Vanicek in
Current site
Google Scholar
PubMed
Close
and
Gerold SiedlerInstitut für Meereskunde, Kiel, Germany

Search for other papers by Gerold Siedler in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Zonal transports of North Atlantic Deep Water (NADW) in the South Atlantic are determined. For this purpose the circulation of intermediate and deep water masses is established on the basis of hydrographic sections from the World Ocean Circulation Experiment (WOCE) and some pre-WOCE sections, using temperature, salinity, nutrients, and anthropogenic tracers. Multiple linear regression is applied to infer missing parameters in the bottle dataset. A linear box-inverse model is used for a set of closed boxes given by sections and continental boundaries. After performing a detailed analysis of water mass distribution, 11 layers are prescribed. Neutral density surfaces are selected as layer interfaces, thus improving the description of water mass distribution in the transition between the subtropical and subpolar latitudes. Constraints for the inverse model include integral meridional salt and phosphorus transports, overall salt and silica conservation, and transports from moored current meter observations. Inferred transport numbers for the mean meridional thermohaline overturning are given. Persistent zonal NADW transport bands are found in the western South Atlantic, in particular eastward flow of relatively new NADW between 20° and 25°S and westward flow of older NADW to the north of this latitude range. The axis of the eastward transport band corresponds to the core of property distributions in this region, suggesting Wüstian flow. Part of the eastward flow appears to cross the Mid-Atlantic Ridge at the Rio de Janeiro Fracture Zone. Results are compared qualitatively with deep float observations and results from general circulation models.

+ Current affiliation: Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

# Additional affiliation: Instituto Canario de Ciencias Marinas, Telde, Spain

Corresponding author address: M. Vanicek, Woods Hole Oceanographic Institution, 360 Woods Hole Road, MS#21, Woods Hole, MA 02543. Email: mvanicek@whoi.edu.

Abstract

Zonal transports of North Atlantic Deep Water (NADW) in the South Atlantic are determined. For this purpose the circulation of intermediate and deep water masses is established on the basis of hydrographic sections from the World Ocean Circulation Experiment (WOCE) and some pre-WOCE sections, using temperature, salinity, nutrients, and anthropogenic tracers. Multiple linear regression is applied to infer missing parameters in the bottle dataset. A linear box-inverse model is used for a set of closed boxes given by sections and continental boundaries. After performing a detailed analysis of water mass distribution, 11 layers are prescribed. Neutral density surfaces are selected as layer interfaces, thus improving the description of water mass distribution in the transition between the subtropical and subpolar latitudes. Constraints for the inverse model include integral meridional salt and phosphorus transports, overall salt and silica conservation, and transports from moored current meter observations. Inferred transport numbers for the mean meridional thermohaline overturning are given. Persistent zonal NADW transport bands are found in the western South Atlantic, in particular eastward flow of relatively new NADW between 20° and 25°S and westward flow of older NADW to the north of this latitude range. The axis of the eastward transport band corresponds to the core of property distributions in this region, suggesting Wüstian flow. Part of the eastward flow appears to cross the Mid-Atlantic Ridge at the Rio de Janeiro Fracture Zone. Results are compared qualitatively with deep float observations and results from general circulation models.

+ Current affiliation: Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

# Additional affiliation: Instituto Canario de Ciencias Marinas, Telde, Spain

Corresponding author address: M. Vanicek, Woods Hole Oceanographic Institution, 360 Woods Hole Road, MS#21, Woods Hole, MA 02543. Email: mvanicek@whoi.edu.

Save