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A change in the freshwater balance of the Atlantic Ocean over the past four decades

Abstract

The oceans are a global reservoir and redistribution agent for several important constituents of the Earth's climate system, among them heat, fresh water and carbon dioxide. Whereas these constituents are actively exchanged with the atmosphere, salt is a component that is approximately conserved in the ocean. The distribution of salinity in the ocean is widely measured, and can therefore be used to diagnose rates of surface freshwater fluxes1, freshwater transport2 and local ocean mixing3—important components of climate dynamics. Here we present a comparison of salinities on a long transect (50° S to 60° N) through the western basins of the Atlantic Ocean between the 1950s and the 1990s. We find systematic freshening at both poleward ends contrasted with large increases of salinity pervading the upper water column at low latitudes. Our results extend a growing body of evidence indicating that shifts in the oceanic distribution of fresh and saline waters are occurring worldwide in ways that suggest links to global warming and possible changes in the hydrologic cycle of the Earth.

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Figure 1: Western Atlantic meridional property sections and surface climatologies.
Figure 2: Western basin meridional property sections versus depth.
Figure 3: Time series of upper ocean salinity anomalies and estimated EP anomalies.

References

  1. Wüst, G. Länderkundliche Forshung 347–359 (Festschrift Norbert Krebs, Stuttgart, 1936)

    Google Scholar 

  2. Wijffels, S., Schmitt, R., Bryden, H. & Stigebrandt, A. Transport of freshwater by the oceans. J. Phys. Oceanogr. 22, 155–162 (1992)

    Article  ADS  Google Scholar 

  3. Lukas, R. & Lindstrom, E. The mixed layer of the Western Equatorial Pacific Ocean. J. Geophys. Res. 96(suppl.), 3343–3357 (1991)

    Article  ADS  Google Scholar 

  4. Levitus, S. Interpentadal variability of salinity in the upper 150m of the North Atlantic Ocean, 1970–1974 versus 1955–1959. J. Geophys. Res. 94, 9679–9685 (1989)

    Article  ADS  Google Scholar 

  5. Deser, C. & Blackmon, M. Surface climate variations over the North Atlantic Ocean during winter: 1900–1989. J. Clim. 6, 1743–1753 (1993)

    Article  ADS  Google Scholar 

  6. Bryden, H. et al. Decadal changes in water mass characteristics at 24°N in the subtropical North Atlantic Ocean. J. Clim. 9, 3162–3186 (1996)

    Article  ADS  Google Scholar 

  7. Joyce, T., Pickart, R. & Millard, R. Long-term hydrographic changes at 52 and 66°W in the North Atlantic subtropical gyre & Caribbean. Deep Sea Res. II 46, 245–278 (1999)

    Article  ADS  Google Scholar 

  8. Lazier, J. et al. in Natural Climate Variability on Decade-to-Century Time Scales (ed. Martinson, D. G.) 295–304 (National Academy Press, Washington DC, 1995)

    Google Scholar 

  9. Blindheim, J. et al. Upper layer cooling and freshening in the Norwegian Sea in relation to atmospheric forcing. Deep-Sea Res. I 47, 655–680 (2000)

    Article  Google Scholar 

  10. Dickson, R. R., Yashayaev, I., Meincke, J., Turrell, W., Dye, S. & Holfort, J. Rapid freshening of the Deep North Atlantic over the past four decades. Nature 416, 832–837 (2002)

    Article  ADS  CAS  Google Scholar 

  11. Schmitt, R., Bogden, P. & Dorman, C. Evaporation minus precipitation and density fluxes for the North Atlantic. J. Phys. Oceanogr. 10, 1210–1221 (1989)

    Google Scholar 

  12. Schmitt, R. W. The ocean component of the water cycle. Rev. Geophys. 33, 1395–1409 (1995)

    Article  ADS  Google Scholar 

  13. Blanke, B., Arhan, M., Lazar, A. & Prevost, G. A Lagrangian numerical investigation of the origins and fates of the Salinity Maximum Water in the Atlantic. J. Geophys. Res. 107, 1–15 (2003)

    Google Scholar 

  14. Roether, W. et al. Recent Changes in the Eastern Mediterranean Deep Waters. Science 271, 333–335 (1996)

    Article  ADS  CAS  Google Scholar 

  15. Dickson, R. R. et al. The Arctic Ocean response to the North Atlantic Oscillation. J. Clim. 13, 2671–2696 (2000)

    Article  ADS  Google Scholar 

  16. Vinje, T. Fram Strait ice fluxes and atmospheric circulation, 1950–2000. J. Clim. 14, 3508–3517 (2001)

    Article  ADS  Google Scholar 

  17. Peterson, B. J. et al. Increasing river discharge to the Arctic Ocean. Science 298, 2171–2173 (2002)

    Article  ADS  CAS  Google Scholar 

  18. Abdalati, W. & Steffen, K. Snowmelt on the Greenland ice sheet as derived from passive microwave satellite data. J. Clim. 10, 165–175 (1997)

    Article  ADS  Google Scholar 

  19. Marshall, J. et al. North Atlantic Climate Variability: phenomena, impacts and mechanisms. Int. J. Clim. 21, 1863–1898 (2001)

    Article  Google Scholar 

  20. Moulin, C., Lambert, C. E., Dulac, F. & Dayan, U. Control of atmospheric export of dust from North Africa by the North Atlantic Oscillation. Nature 387, 691–694 (1997)

    Article  ADS  CAS  Google Scholar 

  21. Peixoto, J. P. & Oort, A. H. Physics of Climate 53 (American Institute of Physics, New York, 1992)

    Google Scholar 

  22. Mignot, J. & Frankignoul, C. On the interannual variability of surface salinity in the Atlantic. Clim. Dyn. 20, 555–565 (2003)

    Article  Google Scholar 

  23. Levitus, S., Antonov, J., Boyer, T. & Stephens, C. Warming of the World Ocean. Science 287, 2225–2229 (2000)

    Article  ADS  CAS  Google Scholar 

  24. Joyce, T. & Robbins, P. The long-term hydrographic record at Bermuda. J. Clim. 9, 3121–3131 (1996)

    Article  ADS  Google Scholar 

  25. Parilla, G., Lavin, A., Bryden, H., Garcia, M. & Millard, R. Rising temperatures in the subtropical North Atlantic Ocean over the past 35 years. Nature 369, 48–51 (1994)

    Article  ADS  Google Scholar 

  26. Wong, A. P. S., Bindoff, N. L. & Church, J. L. Large scale freshening of intermediate waters in the Pacific and Indian Oceans. Nature 400, 440–443 (1999)

    Article  ADS  CAS  Google Scholar 

  27. Wong, A. P. S., Bindoff, N. L. & Church, J. C. Freshwater and heat changes in the North and South Pacific Oceans between the 1960s and 1985–94. J. Clim. 14, 1613–1633 (2001)

    Article  ADS  Google Scholar 

  28. Bindoff, N. L. & McDougall, T. J. Decadal changes along an Indian Ocean Section at 32S and their interpretation. J. Phys. Oceanogr. 30, 1207–1222 (2000)

    Article  ADS  Google Scholar 

  29. Intergovernmental Panel on Climate Change (IPCC). Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the IPCC (eds Houghton, J. T. et al.) (Cambridge Univ. Press, Cambridge, UK, 2001)

    Google Scholar 

  30. Curry, R. G. HydroBase2: A Database of Hydrographic Profiles and Tools for Climatological Analysishttp://www.whoi.edu/science/PO/hydrobase〉 (WHOI, 2002)

    Google Scholar 

Download references

Acknowledgements

We are grateful to J. Toole and R. Schmitt for their encouragement and discussions. This work was supported by an NSF grant and the WHOI Ocean and Climate Change Institute. It has also formed part of the data synthesis phase of the WOCE Program, of the ASOF Project of the US NSF and the Framework V Programme of the European Community, and of the NOAA Consortium on the Ocean's Role in Climate of the Scripps Institution of Oceanography and the Lamont-Doherty Earth Observatory.

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Curry, R., Dickson, B. & Yashayaev, I. A change in the freshwater balance of the Atlantic Ocean over the past four decades. Nature 426, 826–829 (2003). https://doi.org/10.1038/nature02206

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