Advertisement

Climate Dynamics

, Volume 23, Issue 3–4, pp 327–339 | Cite as

A method for obtaining pre-twentieth century initial conditions for use in climate change studies

  • R. J. StoufferEmail author
  • A. J. Weaver
  • M. Eby
Article

Abstract

A method is proposed to initialise coupled atmosphere-ocean general circulation models (AOGCMs) developed to study climate change on multi-century time scales. The method assumes that current generation AOGCMs are developed and evaluated using present-day radiative forcing and near present day oceanic initial conditions. To find pre-twentieth century initial conditions, we propose that the radiative forcing be run backwards in time from the present to the desired starting date. The model should then be run for 3–5 centuries with the radiative forcing held constant at the desired date. In our tests, instantaneously switching to pre-twentieth century radiative forcing did not save computational time. When a sufficiently stable pre-twentieth century condition is achieved, the coupled system can be integrated forward to the present and into the future. This method is a first step toward the standardization of AOGCM initialization and suggests a framework for AOGCM initialization for the first time. It provides an internally consistent set of pre-twentieth century initial conditions, although they will vary from model to model. Furthermore, it is likely that this method will yield a fairly realistic present-day climate in transient climate change experiments of the twentieth century, if the model biases are not too large. The main disadvantage of the method is that it is fairly computationally expensive in that it requires an additional 4–6 centuries of model integration before starting historical twentieth century integrations. However, the relative cost of this technique diminishes as more simulations are conducted using the oceanic initial condition obtained using our method.

Keywords

Radiative Condition Last Glacial Maximum Control Integration Flux Adjustment Cold Start Problem 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

We are indebted to our colleagues in the WCRP WGCM, and especially Larry Gates, and John Mitchell, for many stimulating discussions over many WCRP WGCM meetings, which ultimately lead to the writing of this manuscript. We are also indebted to K. Dixon, T. Delworth, J Meehl and J Gregory for their many thoughtful comments on this work. AJW is also grateful for funding support from the NSERC/CFCAS CLIVAR Program and for release time and funding provided by the Killam Foundation and the Canada Research Chair programs.

References

  1. Bitz CM, Holland MM, Weaver AJ Eby M (2001) Simulating the ice-thickness distribution in a coupled climate model. J Geophys Res 106: 2441–2463CrossRefGoogle Scholar
  2. Dixon KW, Lanzante JR (1999) Global mean surface air temperature and North Atlantic overturning in a suite of coupled GCM climate change experiments. Geophys Res Lett 26: 1881–1888CrossRefGoogle Scholar
  3. Duffy PB, Eby M, Weaver AJ (1999) Effects of sinking of salt rejected during formation of sea ice on results of a global ocean-atmosphere-sea ice climate model. Geophys Res Lett 26: 1739–1742CrossRefGoogle Scholar
  4. Duffy PB, Eby M, Weaver AJ (2001) Climate model simulations of effects of increased atmospheric CO2 and loss of sea ice on ocean salinity and tracer uptake. J Clim 14: 520–532CrossRefGoogle Scholar
  5. Ewen TL, Weaver AJ, Eby M (2004) Sensitivity of the inorganic ocean carbon cycle to future climate warming in the UVic coupled model. Atmosphere-Ocean, (in press)Google Scholar
  6. Fanning AF, Weaver AJ (1996) An atmospheric energy moisture-balance model: climatology, interpentadal climate change and coupling to an OGCM. J Geophys Res 101: 15,111–15,128CrossRefGoogle Scholar
  7. Griffies SM, Harrison MJ, Pacanowski RC, Rosati A (2003) A technical guide to MOM4. GFDL Ocean Group Techn Rep 5, available online at www.gfdl.noaa.govGoogle Scholar
  8. Hasselmann K, Sausen R, Maier-Reimer E,Voss R (1993) On the cold start problem in transient simulations with coupled ocean-atmosphere models. lim Dyn 9: 51–61Google Scholar
  9. Hewitt CD, Stouffer RJ, Broccoli AJ, Mitchell JFB, Valdes PJ (2003) The effect of ocean dynamics in a coupled GCM simulation of the Last Glacial Maximum. Clim Dyn 20: 203–218Google Scholar
  10. Holland MM, Bitz CM, Eby M, Weaver AJ (2001) The role of ice ocean interactions in the variability of the North Atlantic thermohaline circulation. J Clim 14: 656–675CrossRefGoogle Scholar
  11. Hunke EC, Dukowicz JK (1997) An elastic-viscous-plastic model for sea ice dynamics. J Phys Oceanogr 27: 1849–1867CrossRefGoogle Scholar
  12. Levitus S (1982) Climatological atlas of the world ocean NOAA/ERL GFDL Prof Pap 13, Princeton, N.J. USA pp 173 (NTIS PB83-184093)Google Scholar
  13. Levitus S, Burgett R, Boyer TP (1994a) World Ocean atlas 1994, volume 3: salinity. NOAA Atlas NESDIS 3, US Government Printing Office, Washington, D.C. USA pp 111Google Scholar
  14. Levitus S, Boyer TP, Antonov J (1994b) World Ocean Atlas 1994, volume 4: temperature. NOAA Atlas NESDIS 4, US Government Printing Office, Washington, D.C. USA pp 129Google Scholar
  15. Levitus S, Conkright ME, Antonov JI, Baranova O, Boyer TP, Garcia HE, Gelfeld R, Johnson D, Locarnini RA, Murphy PP, O’Brien TD, Smolyar I, Stephens C (2002) World Ocean Database 2001, volume 1: introduction. NOAA Atlas NESDIS 42, U.S. Government Printing Office, Washington, D.C. USA pp 167Google Scholar
  16. Manabe S, Stouffer RJ, Spelman MJ, Bryan K (1991) Transient responses of a coupled ocean-atmosphere model to gradual changes of atmospheric CO2. Part I: Annual mean response. J Clim 4: 785–818CrossRefGoogle Scholar
  17. Matthews HD, Weaver AJ, Eby M, Meissner KJ (2003) Radiative forcing of climate by historical land cover change. Geophys Res Lett 30(2): 27:1–27:4, 1055, doi:10.1029/2002GL016098Google Scholar
  18. Matthews HD, Weaver AJ, Meissner KJ, Gillett NP, Eby M (2004) Natural and anthropogenic climate change: Incorporating historical land cover change, vegetation dynamics and the global carbon cycle. Clim Dyn (in press)Google Scholar
  19. Meissner KJ, Schmittner A, Weaver AJ, Adkins JF (2003a) The ventilation of the North Atlantic Ocean during the Last Glacial Maximum — a comparison between simulated and observed radiocarbon ages. Paleoceanography, 18: 1023 doi:10.1029/2002PA000762Google Scholar
  20. Meissner KJ, Weaver AJ, Matthews HD, Cox PM (2003b) The role of land-surface dynamics in glacial inception: a study with the UVic Earth System Model. Clim Dyn 21: 511–537CrossRefGoogle Scholar
  21. Mitchell JFB, Johns TC, Gregory JM, Tett SFB (1995) Climate response to increasing levels of greenhouse gases and sulphate aerosols. Nature 376: 501–504CrossRefGoogle Scholar
  22. Moore III, B, Gates WL, Mata LJ, Underal A (2001) Advancing our understanding. In: 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 pp 526–582Google Scholar
  23. Ramaswamy V, Boucher O, Haigh J, Hauglustaine D, Haywood J, Myhre G, Nakajima T, Shi GY, Solomon S (2001) IPCC Chapter 5, Advancing our understanding. In: 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 pp 341–416Google Scholar
  24. Schmittner A, Meissner KJ, Eby M, Weaver AJ (2002) Forcing of the deep ocean circulation in simulations of the Last Glacial Maximum. Paleoceanography 17(2): 5:1–5:15, 1015, doi:10.1029/2001PA000633Google Scholar
  25. Stott PA, Tett SFB, Jones GS, Allen MR, Mitchell JFB, Jenkins GJ (2000) External control of twentieth century temperature by natural and anthropogenic forcings. Sci 290: 2131–2137CrossRefGoogle Scholar
  26. Stouffer RJ (2004) Time scales of climate response. J Clim 17: 201–217CrossRefGoogle Scholar
  27. Stouffer RJ, Dixon KW (1998) Initialization of coupled models for use in climate studies: a review. In: research activities in atmospheric and oceanic modelling, Rep 27, WMO/TD-No. 865, World Meteorological Organization, Geneva, Switzerland, pp I.1-I.8Google Scholar
  28. Weaver AJ, Hughes TMC (1996) On the incompatibility of ocean and atmosphere models and the need for flux adjustments. Clim Dyn 13: 141–170CrossRefGoogle Scholar
  29. Weaver AJ, Eby M, Fanning AF, Wiebe EC (1998) Simulated influence of carbon dioxide, orbital forcing and ice sheets on the climate of the last glacial maximum. Nature 394: 847–853CrossRefGoogle Scholar
  30. Weaver AJ, Duffy PB, Eby M, Wiebe EC (2000) Evaluation of ocean and climate models using present-day observations and forcing. Atmosphere-Ocean 38: 271–301Google Scholar
  31. Weaver AJ, Eby M, Wiebe EC, Bitz CM, Duffy PB, Ewen TL, Fanning AF, Holland MM, MacFadyen A, Matthews HD, Meissner KJ, Saenko O, Schmittner A, Wang H, Yoshimori M (2001) The UVic Earth System Climate Model: model description, climatology and application to past, present and future climates. Atmosphere-Ocean 39: 361–428Google Scholar

Copyright information

© Springer-Verlag  2004

Authors and Affiliations

  1. 1.Geophysical Fluid Dynamics LaboratoryPrincetonUSA
  2. 2.School of Earth and Ocean Sciences University of VictoriaVictoriaCanada

Personalised recommendations