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Importance of density-compensated temperature change for deep North Atlantic Ocean heat uptake

Nature Geoscience volume 5, pages 905–910 (2012)Cite this article

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Abstract

The efficiency with which the oceans take up heat has a significant influence on the rate of global warming. Warming of the ocean above 700 m over the past few decades has been well documented. However, most of the ocean lies below 700 m. Here we analyse observations of heat uptake into the deep North Atlantic. We find that the extratropical North Atlantic as a whole warmed by 1.45±0.5×1022 J between 1955 and 2005, but Lower North Atlantic Deep Water cooled, most likely as an adjustment from an early twentieth-century warm period. In contrast, the heat content of Upper North Atlantic Deep Water exhibited strong decadal variability. We demonstrate and quantify the importance of density-compensated temperature anomalies for long-term heat uptake into the deep North Atlantic. These anomalies form in the subpolar gyre and propagate equatorwards. High salinity in the subpolar gyre is a key requirement for this mechanism. In the past 50 years, suitable conditions have occurred only twice: first during the 1960s and again during the past decade. We conclude that heat uptake through density-compensated temperature anomalies will contribute to deep ocean heat uptake in the near term. In the longer term, the importance of this mechanism will be determined by competition between the multiple processes that influence subpolar gyre salinity in a changing climate.

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Figure 1: Heat content, salt and mass anomalies in the extratropical North Atlantic between 1955 and 2005.
Figure 2: Property anomalies, averaged vertically and zonally, within the NADW as a function of time and latitude.
Figure 3: Time series of QHC changes (J) within the four main water masses of the STG.
Figure 4: Maps of depth-average temperature anomalies within UNADW and LNADW for selected 5-year periods.

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  • 22 November 2012

    In the version of this Article originally published online, the y axis labels in Fig. 1a–d were incorrect. The labels are now correct in all versions of the Article.

References

  1. Levitus, S., Antonov, J. & Boyer, T. Warming of the world ocean, 1955–2003. Geophys. Res. Lett. 32, L02604 (2005).

    Google Scholar 

  2. Bindoff, N. L. et al. in IPCC Climate Change 2007: The Physical Science Basis (eds Solomon, S. et al.) (Cambridge Univ. Press, 2007).

    Google Scholar 

  3. Domingues, C. M et al. Improved estimates of upper-ocean warming and multi-decadal sea-level rise. Nature 453, 1090–1093 (2008).

    Article  Google Scholar 

  4. Ishii, M. & Kimoto, M. Reevaluation of historical ocean heat content variations with time-varying XBT and MBT depth bias corrections. J. Oceanograph. 65, 287–299 (2009).

    Article  Google Scholar 

  5. Levitus, S. et al. Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems. Geophys. Res. Lett. 36, L07608 (2009).

    Google Scholar 

  6. Purkey, S. & Johnson, G. Warming of global abyssal and deep southern ocean waters between the 1990s and 2000s: Contributions to global heat and level rise budgets. J. Clim. 23, 6336–6351 (2010).

    Article  Google Scholar 

  7. Song, Y. & Colberg, F. Deep ocean warming assessed from altimeters, gravity recovery and climate experiment, in situ measurements, and a non-Boussinesq ocean general circulation model. J. Geophys. Res. 116, C02020 (2011).

    Google Scholar 

  8. Trenberth, K. Global change: The ocean is warming, isn’t it? Nature 465, 304 (2010).

    Article  Google Scholar 

  9. Lozier, M. S. et al. The spatial pattern and mechanisms of heat-content change in the North Atlantic. Science 319, 800–803 (2008).

    Article  Google Scholar 

  10. Ganachaud, A. & Wunsch, C. Large-scale ocean heat and freshwater transports during the World Ocean Circulation Experiment. J. Clim. 16, 696–705 (2003).

    Article  Google Scholar 

  11. Lumpkin, R. & Speer, K. Global ocean meridional overturning. J. Phys. Oceanograph. 37, 2550–2562 (2007).

    Article  Google Scholar 

  12. Talley, L. Freshwater transport estimates and the global overturning circulation: shallow, deep and throughflow components. Prog. Oceanograph. 78, 257–303 (2008).

    Article  Google Scholar 

  13. Dickson, R. et al. Long-term coordinated changes in the convective activity of the North Atlantic. Prog. Oceanograph. 38, 241–295 (1996).

    Article  Google Scholar 

  14. Curry, R. G. & McCartney, M. S. Ocean gyre circulation changes associated with the North Atlantic Oscillation. J. Phys. Oceanograph. 31, 3374–3400 (2001).

    Article  Google Scholar 

  15. Visbeck, M. et al. The ocean’s response to North Atlantic Oscillation variability. in The North Atlantic Oscillation: Climatic Significance and Environmental Impacts Vol. 134 (eds Hurrell, J. W., Kushnir, J. W., Ottersen, Y. & Visbeck, G.) (Geophysical Monograph Series, American Geophysical Union, 2003).

    Google Scholar 

  16. Munk, W. & Wunsch, C. Abyssal recipes II: energetics of tidal and wind mixing. Deep-Sea Res. 45, 1977–2010 (1998).

    Article  Google Scholar 

  17. Bindoff, N. L. & McDougall, T. J. Diagnosing climate change and ocean ventilation using hydrographic data. J. Phys. Oceanograph. 24, 1137–1152 (1994).

    Article  Google Scholar 

  18. Curry, R. G. et al. Oceanic transport of subpolar climate signals to mid-depth subtropical waters. Nature 391, 575–577 (1998).

    Article  Google Scholar 

  19. Yashayaev, I., van Aken, H. M., Holliday, N. P. & Bersch, M. Transformation of the Labrador Sea Water in the subpolar North Atlantic. Geophys. Res. Lett. 34, L22605 (2007).

    Article  Google Scholar 

  20. Yashayaev, I. & Clarke, A. Evolution of North Atlantic water masses inferred from Labrador Sea salinity series. Oceanography 21, 30–45 (2008).

    Article  Google Scholar 

  21. Johnson, G. C. & Wijffels, S. E. Ocean density change contributions to sea level rise. Oceanography 24, 112–121 (2011).

    Article  Google Scholar 

  22. Lozier, M. S. et al. Opposing decadal changes for the North Atlantic meridional overturning circulation. Nature Geosci. 3, 728–734 (2010).

    Article  Google Scholar 

  23. Levitus, S., Antonov, J. I., Boyer, T. P. & Stephens, C. Warming of the world ocean. Science 287, 2225–2229 (2000).

    Article  Google Scholar 

  24. Yashayaev, I. Hydrographic changes in the Labrador Sea, 1960–2005. Prog. Oceanograph. 73, 242–276 (2007).

    Article  Google Scholar 

  25. Sarafanov, A. On the effect of the North Atlantic Oscillation on the temperature and salinity of the subpolar North Atlantic intermediate and deep waters. ICES J. Mar. Sci. 66, 1448–1454 (2009).

    Article  Google Scholar 

  26. Talley, L. D. & McCartney, M. S. Distribution and circulation of Labrador Sea Water. J. Phys. Oceanograph. 12, 1189–1205 (1982).

    Article  Google Scholar 

  27. Fine, R. A. & Molinary, R. L. A continuous deep western boundary Current between Abaco (26.5°N) and Barbados (13°N). Deep-Sea Res. A 35, 1441–1450 (1988).

    Article  Google Scholar 

  28. Sebille, E. v. et al. Propagation pathways of classical Labrador Sea Water from its source region to 26°N. J. Geophys. Res. 116, C12027 (2011).

    Article  Google Scholar 

  29. Leadbetter, S. J., Williams, R. G., McDonagh, E. L & King, B. A. A twenty year reversal in water mass trends in the subtropical North Atlantic. Geophys. Res. Lett. 34, L12608 (2007).

    Article  Google Scholar 

  30. Rhein, M. The Deep Western Boundary Current: Tracers and velocities. Deep-Sea Res. I 41, 263–281 (1994).

    Article  Google Scholar 

  31. Robson, J., Sutton, R., Lohmann, K., Smith, D. & Palmer, M. D. Causes of the rapid warming of the North Atlantic Ocean in the Mid-1990s. J. Clim. 25, 4116–4134 (2012).

    Article  Google Scholar 

  32. Koltermann, K. P. et al. Decadal changes in the thermohaline circulation of the North Atlantic. Deep-Sea Res. II 46, 109–138 (1999).

    Article  Google Scholar 

  33. Bower, A., Lozier, M., Gary, S. & Boning, C. Interior pathways of the North Atlantic meridional overturning circulation. Nature 459, 243–247 (2009).

    Article  Google Scholar 

  34. Drinkwater, K. The regime shift of the 1920s and 1930s in the North Atlantic. Prog. Oceanograph. 68, 134–151 (2006).

    Article  Google Scholar 

  35. Johnson, G., Purkey, S. & Toole, J. Reduced Antarctic meridional overturning circulation reaches the North Atlantic Ocean. Geophys. Res. Lett. 35, L22601 (2008).

    Article  Google Scholar 

  36. Holliday, N. P. et al. Reversal of the 1960s to 1990s freshening trend in the northeast North Atlantic and Nordic Seas. Geophys. Res. Lett. 35, L03614 (2008).

    Article  Google Scholar 

  37. Hughes, S. L., Holliday, N. P. & Beszczynska-Möller, A. ICES Report on Ocean Climate 2009. ICES Cooperative Research Report, 304, 67pp (2010).

  38. Stott, P. A., Sutton, R. T. & Smith, D. M. Detection and attribution of Atlantic salinity changes. Geophys. Res. Lett. 35, L21702 (2008).

    Article  Google Scholar 

  39. Lozier, M. S., Owens, W. B. & Curry, R.G. The climatology of the North Atlantic. Prog. Oceanograph. 36, 1–44 (1995).

    Article  Google Scholar 

  40. Curry, R. & Mauritzen, C. Dilution of the northern North Atlantic Ocean in recent decades. Science 308, 1772–1774 (2005).

    Article  Google Scholar 

  41. Curry, R. HydroBase 2: A database of hydrographic profiles and tools for climatological analysis. Available from http://www.whoi.edu/science/PO/hydrobase. 81 pp (2001).

  42. Hurrell, J. W. & Deser, C. North Atlantic climate variability: The role of the North Atlantic Oscillation. J. Mar. Syst. 79, 231–244 (2010).

    Article  Google Scholar 

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Acknowledgements

C.M. and A.M. acknowledge the support of the Norwegian Research Council through iAOOS-Norway (grant number 176096) and the European Union through its 6th Framework Programme Integrated Project DAMOCLES. R.T.S. acknowledges the support of the UK National Centre for Atmospheric Science and the Natural Environment Research Council. We thank J. Gregory and R. Tailleux for valuable comments on the manuscript. We thank R. G. Curry for providing the new Atlantic Ocean analyses, and for valuable assistance with the data analysis at the initial stages of the project.

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Author notes

  1. C. Mauritzen

    Present address: Present address: CICERO Center for International Climate and Environmental Research—Oslo, 0318 Oslo, Norway,

Authors and Affiliations

  1. Norwegian Meteorological Institute, 0313 Oslo, Norway

    C. Mauritzen & A. Melsom

  2. National Centre for Atmospheric Science, University of Reading, Reading RG6 6BB, UK

    R. T. Sutton

Authors
  1. C. Mauritzen
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Contributions

C.M. led the study, and performed with A.M. and R.T.S. the analysis and interpretation. A.M. formulated the density space approach and the error analysis, and wrote the Supplementary Information. C.M. and R.T.S. jointly wrote the paper. All authors discussed the results and made comments on the manuscript.

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Correspondence to C. Mauritzen.

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Mauritzen, C., Melsom, A. & Sutton, R. Importance of density-compensated temperature change for deep North Atlantic Ocean heat uptake. Nature Geosci 5, 905–910 (2012). https://doi.org/10.1038/ngeo1639

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