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Simulating the winter North Atlantic Oscillation: the roles of internal variability and greenhouse gas forcing

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Abstract

Analysis of simulations with seven coupled climate models demonstrates that the observed variations in the winter North Atlantic Oscillation (NAO), particularly the increase from the 1960s to the 1990s, are not compatible with either the internally generated variability nor the response to increasing greenhouse gas forcing simulated by these models. The observed NAO record can be explained by a combination of internal variability and greenhouse gas forcing, though only by the models that simulate the strongest variability and the strongest response. These models simulate inter-annual variability of the NAO index that is significantly greater than that observed, and can no longer explain the observed record if the simulated NAO indices are scaled so that they have the same high-frequency variance as that observed. It is likely, therefore, that other external forcings also contributed to the observed NAO index increase, unless the climate models are deficient in their simulation of inter-decadal NAO variability or their simulation of the response to greenhouse gas forcing. These conclusions are based on a comprehensive analysis of the control runs and transient greenhouse-gas-forced simulations of the seven climate models. The simulations of mean winter circulation and its pattern of inter-annual variability are very similar to the observations in the Atlantic half of the Northern Hemisphere. The winter atmospheric circulation response to increasing greenhouse gas forcing shows little inter-model similarity at the regional scale, and the NAO response is model-dependent and sensitive to the index used to measure it. At the largest scales, however, sea level pressure decreases over the Arctic Ocean in all models and increases over the Mediterranean Sea in six of the seven models, so that there is an increase of the NAO in all models when measured using a pattern-based index.

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References

  • Bacher A, Oberhuber JM, Roeckner E (1998) ENSO dynamics and seasonal cycle in the tropical Pacific as simulated by the ECHAM4/OPYC3 coupled general circulation model. Clim Dyn 14: 1659–1672

    Google Scholar 

  • Basnett TA, Parker DE (1997) Development of the global mean sea level pressure data set GMSLP2. Hadley Centre Climate Research Technical Note 79, Met Office, Bracknell, UK

  • Castanheira JM, Graf H-F (2003) North Pacific–North Atlantic relationships under stratospheric control. J Geophys Res 108: 4036 DOI 10.1029/2002JD002754

    Google Scholar 

  • Cubasch U, Meehl GA, Boer GJ, Stouffer RJ, Dix M, Noda A, Senior CA, Raper S, Yap KS (2001) Projections of future climate change. In: Houghton JT, Ding Y, Griggs DJ, Noguer M, van der Linden PJ, Dai X, Maskell K, Johnson CA (eds) Climate change 2001: the scientific basis. Contribution of Working Group I to the third assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, USA, pp 525–582

  • Emori S, Nozawa T, Abe-Ouchi A, Numaguti A, Kimoto M, Nakajima T (1999) Coupled ocean-atmosphere model experiments of future climate change with an explicit representation of sulfate aerosol scattering. J Meteorol Soc Japan 77: 1299–1307

    Google Scholar 

  • Flato GM, Boer GJ, Lee WG, McFarlane NA, Ramsden D, Reader MC, Weaver AJ (2000) The Canadian Centre for Climate Modelling and Analysis global coupled model and its climate. Clim Dyn 16: 451–467

    Google Scholar 

  • Fyfe JC, Boer GJ, Flato GM (1999) The Arctic and Antarctic Oscillations and their projected changes under global warming. Geophys Res Lett 26: 1601–1604

    Google Scholar 

  • Gillett NP, Hegerl GC, Allen MR, Stott PA (2000) Implications of changes in the Northern Hemisphere circulation for the detection of anthropogenic climate change. Geophys Res Lett 27: 993–996

    Google Scholar 

  • Gillett NP, Baldwin MP, Allen MR (2001) Evidence for nonlinearity in observed stratospheric circulation changes. J Geophys Res 106: 7891–7901

    Google Scholar 

  • Gillett NP, Allen MR, McDonald RE, Senior CA, Shindell DT, Schmidt GA (2002) How linear is the Arctic Oscillation response to greenhouse gases. J Geophys Res 107: DOI 10.1029/2001JD000589

    Google Scholar 

  • Gillett NP, Graf HF, Osborn TJ (2003) Climate change and the North Atlantic Oscillation. In: Hurrell JW, Kushnir Y, Ottersen G, Visbeck M (eds) North Atlantic Oscillation: climatic significance and environmental impact. (Geophysical Monograph 134) American Geophysical Union, Washington, pp 193–209 DOI 10.1029/134GM09

  • Gordon HB, O’Farrell SP (1997) Transient climate change in the CSIRO coupled model with dynamic sea ice. Mon Weather Rev 125: 875–907

    Google Scholar 

  • Gordon C, Cooper C, Senior CA, Banks H, Gregory JM, Johns TC, Mitchell JFB, Wood RA (2000) The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjusments. Clim Dyn 16: 147–168

    Google Scholar 

  • Hilmer M, Jung T (2000) Evidence for a recent change in the link between the North Atlantic Oscillation and Arctic sea ice export. Geophys Res Lett 27: 989–992

    Google Scholar 

  • Hurrell JW (1995) Decadal trends in the North Atlantic Oscillation: regional temperatures and precipitation. Science 269: 676–679

    Google Scholar 

  • Hurrell JW (1996) Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere temperature. Geophys Res Lett 23: 655–668

    Google Scholar 

  • Johns TC, Carnell RE, Crossley JF, Gregory JM, Mitchell JFB, Senior CA, Tett SFB, Wood RA (1997) The second Hadley Centre coupled ocean-atmosphere GCM: model description, spinup and validation. Clim Dyn 13: 103–134

    Google Scholar 

  • Jones PD (1987) The early twentieth century Arctic High – fact or fiction? Clim Dyn 1: 63–75

    Google Scholar 

  • Jones PD, Jonsson T, Wheeler D (1997) Extension to the North Atlantic Oscillation using early instrumental pressure observations from Gibraltar and South-West Iceland. Int J Climatol 17: 1433–1450

    Google Scholar 

  • Lambert SJ, Boer GJ (2001) CMIP1 evaluation and intercomparison of coupled climate models. Clim Dyn 17: 83–106

    Google Scholar 

  • Mitchell JFB, Johns TC, Eagles M, Ingram WJ, Davis RA (1999) Towards the construction of climate change scenarios. Clim Change 41: 547–581

    Google Scholar 

  • Osborn TJ, Briffa KR, Tett SFB, Jones PD, Trigo RM (1999) Evaluation of the North Atlantic Oscillation as simulated by a coupled climate model. Clim Dyn 15: 685–702

    Google Scholar 

  • Ostermeier GM, Wallace JM (2003) Trends in the North Atlantic Oscillation–Northern Hemisphere annular mode during the twentieth century. J Clim 16: 336–341

    Google Scholar 

  • Paeth H, Hense A, Glowienka-Hense R, Voss R, Cubasch U (1999) The North Atlantic Oscillation as an indicator for greenhouse-gas induced regional climate change. Clim Dyn 15: 953–960

    Google Scholar 

  • Peterson KA, Lu J, Greatbatch RJ (2003) Evidence of nonlinear dynamics in the eastward shift of the NAO. Geophys Res Lett 30: 1030 DOI 10.1029/2002GL015585

    Google Scholar 

  • Rodwell MJ, Rowell DP, Folland CK (1999) Oceanic forcing of the wintertime North Atlantic Oscillation and European climate. Nature 398: 320–323

    Google Scholar 

  • Shindell DT, Miller RL, Schmidt GA, Pandolfo L (1999) Simulation of recent northern winter climate trends by greenhouse-gas forcing. Nature 399: 452–455

    Google Scholar 

  • Stephenson DB, Pavan V (2003) The North Atlantic Oscillation in coupled climate models: a CMIP1 evaluation. Clim Dyn 20: 381–399

    Google Scholar 

  • Stephenson DB, Pavan V, Bojariu R (2000) Is the North Atlantic Oscillation a random walk? Int J Climatol 20: 1–18

    Google Scholar 

  • Stott PA, Tett SFB, Jones GS, Allen MR, Mitchell JFB, Jenkins GJ (2000) External control of 20th century temperature by natural and anthropogenic forcings. Science 290: 2133–2137

    Google Scholar 

  • Thompson DWJ, Wallace JM (1998) The Arctic Oscillation signature in the wintertime geopotential height and temperature fields. Geophys Res Lett 25: 1297–1300

    Google Scholar 

  • Thompson DWJ, Wallace JM, Hegerl GC (2000) Annular modes in the extratropical circulation. Part II: trends. J Clim 13: 1018–1036

    Google Scholar 

  • Ulbrich U, Christoph M (1999) A shift of the NAO and increasing storm track activity over Europe due to anthropogenic greenhouse gas forcing. Clim Dyn 15: 551–559

    Google Scholar 

  • van Loon H, Rogers J (1978) The seesaw in winter temperature between Greenland and northern Europe. Part I: general description. Mon Weather Rev 106: 296–310

    Google Scholar 

  • Walker GT (1924) Correlations in seasonal variations of weather IX. Mem Ind Meteorol Dept 24, 275–332

    Google Scholar 

  • Wanner H, Bronnimann S, Casty C, Gyalistras D, Luterbacher J, Schmutz C, Stephenson DB, Xoplaki E (2001) North Atlantic Oscillation – concepts and studies. Surv Geophys 22: 321–382

    Google Scholar 

  • Washington WM, Weatherly JW, Meehl GA, Semtner Jr AJ, Bettge TW, Craig AP, Strand Jr WG, Arblaster JM, Wayland VB, James R, Zhang Y (2000) Parallel climate model (PCM) control and transient simulations. Clim Dyn 16 755–774

    Google Scholar 

  • Zorita E, Gonzalez-Rouco F (2000) Disagreement between predictions of the future behaviour of the Arctic Oscillation as simulated in two different climate models: implications for global warming. Geophys Res Lett 27: 1755–1758

    Google Scholar 

Download references

Acknowledgements

This study was supported by the Commission of the European Communities (SO&P, EVK2-CT-2002-00160), with additional support from the Tyndall Centre for Climate Change Research (IT1.15). All modelling centres are gratefully acknowledged for making their data available, and David Viner is thanked for his assistance in obtaining the data. Updated Met Office SLP data were provided by British Atmospheric Data Centre (BADC). Simon Tett, Keith Briffa, Phil Jones and David Stephenson provided useful guidance at various stages of this work. The constructive comments provided by two reviewers helped to improve this paper.

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Osborn, T.J. Simulating the winter North Atlantic Oscillation: the roles of internal variability and greenhouse gas forcing. Climate Dynamics 22, 605–623 (2004). https://doi.org/10.1007/s00382-004-0405-1

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