Start Submission Become a Reviewer

Reading: Scaling of the strength of the meridional overturning with vertical diffusivity in an ideali...

Download

A- A+
Alt. Display

Original Research Papers

Scaling of the strength of the meridional overturning with vertical diffusivity in an idealized global geometry

Authors:

Matthijs Den Toom ,

Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, NL
X close

Henk A. Dijkstra

Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, NL
X close

Abstract

An important expression of the non-linear character of the ocean’s meridional overturning circulation (MOC) is the scaling of its amplitude with the magnitude of the vertical mixing coefficient (diffusivity) of heat and salt. This paper extends recent work that indicated that the Atlantic and Pacific MOC exhibit different scaling behaviour. An idealized two-basin model configuration is used to study the meridional overturning circulation under restoring boundary conditions. In particular, the effects of wind forcing and the choice of the parametrization of lateral mixing are examined.

Without wind, the scaling is similar in the two basins and consistent with theoretical predictions, provided that the diffusivity is small enough. Towards higher diffusivities the scaling of the overturning diverges. With non-zero wind, the sensitivity is strongly determined by the choice of the lateral mixing scheme. In case of traditional horizontal diffusion, the scaling behaviour is asymmetric due to spurious diapycnal mixing. With the Gent-McWilliams parametrization, the scaling is symmetric for the lower range of diffusivities, where results agree partly with theoretical scaling relations. In all cases considered, the pycnocline depth has the same sensitivity to diffusivity in both basins, implying that there is no universally valid relation between overturning strength and pycnocline depth.

How to Cite: Toom, M.D. and Dijkstra, H.A., 2011. Scaling of the strength of the meridional overturning with vertical diffusivity in an idealized global geometry. Tellus A: Dynamic Meteorology and Oceanography, 63(2), pp.354–370. DOI: http://doi.org/10.1111/j.1600-0870.2010.00496.x
2
Citations
  Published on 01 Jan 2011
 Accepted on 20 Sep 2010            Submitted on 11 Jan 2009

References

  1. Anderson , D. , Stockdale , T. , Balmaseda , M. , Ferranti , L. , Vitart , F. and co-authors . 2006 . Seasonal Forecast System 3. ECMWF Newsletter , 19 - 25 .  

  2. Balmaseda , M. , Freeanti , L. , Molteni , F. and Palmer , T. N . 2009 . Impact of 2007 and 2008 Arctic Ice Anomalies on the Atmospheric Circulation: Implications for Long-Range Predictions. Technical Memorandum 595. ECMWF , http://www.ecmwf.int/publications/library/do/references/list/show?id=89212 .  

  3. Balmaseda , M. A. , Vidard , A. and Anderson , D. L. T . 2007 . The ECMWF System 3 ocean analysis system . Technical Memorandum 508. ECMWF.  

  4. Balmaseda , M. A. , Ferranti , L. , Molteni , F. and Palmer , T. N . 2010 . Impact of 2007 and 2008 Arctic ice anomalies on the atmo-spheric circulation: implications for long-range predictions. QJRMS , https://doi.org/10.1002/qj.661 .  

  5. Benestad , R. E . 2005 . On Latitudinal Profiles of Zonal Means. Geophys. Res. Lett . 32 , https://doi.org/10.1029/2005GL023652 .  

  6. Benestad , R. E . 2006 . Can we expect more extreme precipitation on the monthly time scale? J. Clim . 19 , 630 – 637 .  

  7. Benestad , R. E. and Chen , D . 2006 . The use of a Calculus-based Cy-clone Identification method for generating storm statistics . Tellus , 58A , 473 – 486 , https://doi.org/10.1111/j.1600-0870.2006.00191.x .  

  8. Benestad , R. E. , Hanssen-Bauer , I. and Forland , E . J . 2002 . Empirically downscaled temperature scenarios for Svalbard. Atm. Sci. Lett., 3, Issue 2-4 , https://doi.org/10.1006/asle.2002 . 0051 , 71 - 93 .  

  9. Derome , J. , Brunet , G. , Plante , A. , Gagnon , N. , Boer , G. J. and co-authors. 2001. Seasonal Predictions Based on Two Dynamical Mod-els. Atm.-Ocean , 39 ( 4 ), 485 - 501 .  

  10. Deser , C. , Magnusdottir , G. , Saravanan , R. and Phillips , A . 2004 . The effects of North Atlantic SST and Sea Ice Anomalies on the Winter Circulation in CCM3. Part II: direct and indirect components of the response . J. Clim . 17 , 877 – 889 .  

  11. Dix , M. R. and Hunt , B. G . 1995 . Chaotic influences and the problem of deterministic seasonal predictions . Int. J. Climatol . 15 ( 7 ), 729 – 752 .  

  12. Doblas-Reyes , F. J. , Hagedorn , R. and Palmer , T. N . 2007 . Develop-ments in dynamical seasonal forecasting relevant to agricultural man-agement . Clim. Res . 33 , 19 – 26 .  

  13. Francis , J. A. , Chan , W. , Leathers , D. J. , Miller , J. R. and Veron , D. E. 2009 . Winter Northern Hemisphere weather patterns remem-ber summer Arctic sea ice extent. Geophys. Res. Lett. 36, L07503 https://doi.org/10.1029/2009GL037274 .  

  14. Hill , T. and Lewicici , P . 2005 . Statistics: Methods and Applications : A Comprehensive Reference for Science , Industry, and Data Mining. Tulsa, OK, USA : StatSoft .  

  15. Holland , M. M. , bitz , C. M. and Tremblay , B . 2006 . Future abrupt reductions in the summer Arctic sea ice . Geophys. Res. Lett . 33 , L23503 , https://doi.org/10.1029/2006GL028024 .  

  16. Johansson , A . 2007 . Prediction skill of the NAO and PNA from Daily to Seasonal Time Scales . J. Clim . 20 , 1957 – 1975 .  

  17. Kauker , F. , Kaminski , T. , Karcher , M. , Giering , R. , Gerdes , R. and co-authors . 2009 . Adjoint analysis of the 2007 all time Arctic sea-ice min-imum. Geophys. Res. Lett . 36 , L03707 , https://doi.org/10.1029/2008GL036323 .  

  18. Kundzewicz , Z. W. , Mata , L. J. , Arnell , N. , Doll , P. , Kabat , P. and co-authors . 2007 . Climate Change: Impacts, Adaptation and Vulnerabilit . Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge Univer-sity Press, United Kingdom and New York, NY, USA.  

  19. Lorenz , E . 1967 . The Nature and Theory of the General Circulation of the Atmosphere . Publication 218. World Meteorological Organization, Geneva, Switzerland.  

  20. Magnusdottir , G. , Deser , C. and Saravanan , R . 2004 . The Effects of North Atlantic SST and Sea Ice Anomalies on the Winter Circulation in CCM3. Part I:Main Features and Storm Track Characteristics of the Response . J. Clim . 17 , 857 – 875 .  

  21. Meehl , G. A. , Stocker , T. F. , Idlingstein , W. D. , Gaye , A. T. , Gre-gory , J. M. , Kitoh , A. , Knutti , R. , Murphy , J. M. , Noda , A. , Raper , S. C. B. , Watterson , I. G. , Weaver , A. J. , Zhao , Z.-C . 2007 . Climate Change: The Physical Science Basis. Chap. Global Climate Projections. United Kingdom and New York, NY, USA. Cambridge University Press.  

  22. Melsom , A . 2009 . Ocean sea ice atmosphere heat fluxes over the Arctic Ocean . Note 14/2009. met.no, http://met.no/Forskning/Publilcasjoner_2009.  

  23. Overland , J. E. and Wang , M . 2010 . Large-scale atmospheric circulation changes are associated with the recent loss of Arctic sea ice . Tellus A . 62 , 1 – 9 .  

  24. Persson , A. and Grazzini , F . 2005 . User Guide to ECMWF forecast products . Meteorological Bulletin M3.2. ECMWF, www.ecmwtint/products/forecasts/guide/user_guide.pdf.  

  25. RDevelopment Core Team . 2004 . R: A language and environment for statistical computing . R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0.  

  26. Reynolds , R. W. , Rayner , N. R. , Smith , T. M. , Stokes , D. C. and Wang , W . 2002 . An improved in situ and satellite SST analysis for climate . J. Clim . 15 , 1609 – 1625 .  

  27. Rowell , D. P . 1998 . Assessing Potential Seasonal Predictability with an Ensemble of Multidecadal GCM Simulations . J. Clim . 11 , 109 – 120 .  

  28. Seierstad , I. A. and Bader , J . 2008 . Impact of a projected future Arctic Sea Ice reduction on extratropical storminess and the NAO . Clim. Dynam . 33 , 937 – 943 .  

  29. Senan , R. and Benestad , R. E . 2009 . Transitional irregularity in sea surface temperature from the ECMWF operational ocean analysis. Note 22. met.no, www.met.no.  

  30. Serreze , M. C. , Barrett , A. P. , Stroeve , J. C. , Kindig , D. N. and Holland , M. M . 2009 . The emergence of surface-based Arctic amplification . The Ciyosphere 3 , 11 – 19 https://doi.org/10.5194/tc-3-11-2009 .  

  31. Singarayer , J. S. , Bamber , J. L. and Valdes , P. J . 2006 . Twenty-first-Century Impacts from a Declining Arctic Sea Ice Cover . J. Clim . 19 , 1109 – 1125 .  

  32. Sivakumar , M. V. K . 2007 . climate prediction and agriculture: current status and future challenges . Clim. Res . 33 , 3 – 17 .  

  33. Sorteberg , A. and Kvingedal , B . 2006 . Atmospheric Forcing on the Barents Sea Winter Ice Extent . J. Clim . 19 , 4772 – 4784 .  

  34. Stockdale , T. N. , Anderson , D. L. T. , Alves , J. O. S. and Balmaseda , M. A. 1998. Global seasonal rainfall forecasts using a coupled ocean-atmosphere model. Nature 392 , 370 - 373 .  

  35. Stroeve , J. , Holland , M. M. , Meier , W. , Scambos , T. and Serreze , M . 2007 . Artie sea ice decline: Faster than forecast . Geophys. Res. Lett . 34 , L09501 https://doi.org/10.1029/3007GL029703 .  

  36. Stroeve , J. , Serreze , M. , Drobot , S. , Gearheard , S. , Holland , M. and co-authors . 2008 . Arctic Sea Ice Extent Plummets in 2007. Eos 89 ( 2 ), 13 - 14 .  

  37. Wilkinson , G. N. and Rogers , C. E . 1973 . Symbolic Description of Factorial Models for Analysis of Variance . AppL StaL 22 , 392 – 399 .  

  38. Wilks , D. S . 2006 . On “Field Significance” and the False Discovery Rate J. Appl. MeteoroL ClimatoL 45 , 1181 - 1189 https://doi.org/10.1175/JAM2404.1 .  

  39. Willcs , D. S . 1995 . Statistical Methods in the Atmospheric Sciences . Orlando, Florida, USA , Academic Press .  

  40. Yan , Z. , Bate , S. , Chandler , R. E. , Isham , V. and Wheater , H . 2006 . Changes in extreme wind speeds in NW Europe simulated by generalized linear models . Theoret. AppL Climatol . 83 , 121 – 137 .  

comments powered by Disqus