Climate Dynamics

, Volume 39, Issue 11, pp 2631–2657 | Cite as

A look at the ocean in the EC-Earth climate model

  • Andreas SterlEmail author
  • Richard Bintanja
  • Laurent Brodeau
  • Emily Gleeson
  • Torben Koenigk
  • Torben Schmith
  • Tido Semmler
  • Camiel Severijns
  • Klaus Wyser
  • Shuting Yang


EC-Earth is a newly developed global climate system model. Its core components are the Integrated Forecast System (IFS) of the European Centre for Medium Range Weather Forecasts (ECMWF) as the atmosphere component and the Nucleus for European Modelling of the Ocean (NEMO) developed by Institute Pierre Simon Laplace (IPSL) as the ocean component. Both components are used with a horizontal resolution of roughly one degree. In this paper we describe the performance of NEMO in the coupled system by comparing model output with ocean observations. We concentrate on the surface ocean and mass transports. It appears that in general the model has a cold and fresh bias, but a much too warm Southern Ocean. While sea ice concentration and extent have realistic values, the ice tends to be too thick along the Siberian coast. Transports through important straits have realistic values, but generally are at the lower end of the range of observational estimates. Exceptions are very narrow straits (Gibraltar, Bering) which are too wide due to the limited resolution. Consequently the modelled transports through them are too high. The strength of the Atlantic meridional overturning circulation is also at the lower end of observational estimates. The interannual variability of key variables and correlations between them are realistic in size and pattern. This is especially true for the variability of surface temperature in the tropical Pacific (El Niño). Overall the ocean component of EC-Earth performs well and helps making EC-Earth a reliable climate model.


Climate model NEMO ocean model: general ocean circulation Surface fluxes Sea ice Ocean heat transport 



We thank ECMWF (Reading, UK), IPSL (Paris, France) and CERFACS (Toulouse, France) for providing us with the IFS, NEMO and OASIS codes, respectively. Simona Ştefǎnescu (ECMWF), Sébastien Masson (IPSL) and Sophie Valcke (CERFACS) provided valuable advice in using them. Computing time to run the model has been provided by ECMWF and ICHEC (Irish Centre for High End Computing). The Kaplan SST V2 data were provided by NOAA/OAR/ESRL PSD (Boulder, Colorado, USA) via their web site ( A large part of the plotting was done using Ferret, which is available from NOAA/PMEL at Part of the analysis was done using the CDF-TOOLS package, which was kindly provided by J.M. Molines, Laboratoire des Ecoulements Géophysiques et Industriels, Grenoble, France. TS received funding from the European Community’s 7th Framework Programme (FP7/2007-2013) under grant agreement No. GA212643 (THOR: “Thermohaline Overturning at Risk”, 2008–2012).


  1. Antonov JI, Seidov D, Boyer TP, Locarnini RA, Mishonov AV, Garcia HE, Baranova OK, Zweng MM, Johnson DR (2010) World Ocean Atlas 2009, volume 2: Salinity. In: Levitus S (ed) NOAA Atlas NESDIS 69. U.S. Government Printing Office, Washington, DCGoogle Scholar
  2. Arakawa A, Lamb VR (1977) Computational design of the basic dynamical processes of the UCLA General Circulation Model. Meth Comp Phys 17:173–265Google Scholar
  3. Balsamo G, Viterbo P, Beljaars A, van den Hurk BJJM, Betts A, Scipal K (2009) A revised hydrology for the ECMWF model: Verification from field site to terrestrial water storage and impact in the integrated forecast system. J Hydrometeorol 10:623–643CrossRefGoogle Scholar
  4. Barnier B, Brodeau L, Le Sommer J, Molines J-M, Penduff T, Theetten S, Treguier A-M, Madec G, Biastoch A, Böning C, Dengg J, Gulev S, Bourdallé Badie R, Chanut J, Garric G, Alderson S, Coward A, de Cuevas B, New A, Haines K, Smith G, Drijfhout S, Hazeleger W, Severijns C, Myers P (2007) Eddy-permitting ocean circulation hindcasts of past decades. Clivar Exchanges 12:8–10Google Scholar
  5. Bechtold P, Köhler M, Jung T, Leutbecher M, Rodwell M, Vitart F, Balsamo G (2008) Advances in predicting atmospheric variability with the ECMWF model, 2008: From synoptic to decadal time-scales. Q J R Meteorol Soc 134:1337–1351CrossRefGoogle Scholar
  6. Belchansky GI, Douglas DC, Platonov NG (2008) Fluctuating Arctic sea ice thickness changes estimated by an in-situ learned and empirically forced neural network model. J Clim 21:716–729. doi: 10.1175/2007JCLI1787.1 CrossRefGoogle Scholar
  7. Biastoch A, Böning C, Getzlaff J, Moline J-M, Madec G (2008) Causes of interannualdecadal variability in the meridional overturning circulation of the Midlatitude North Atlantic Ocean. J Clim 21:6599–6615. doi: 10.1175/2008JCLI2404.1 CrossRefGoogle Scholar
  8. Bouillon S, Morales Maqueda MA, Legat V, Fichefet T (2009) An elastic-viscous-plastic sea ice model formulated on Arakawa B and C grids. Ocean Modell 27:174–184. doi: 10.1016/j.ocemod.2009.01.004 CrossRefGoogle Scholar
  9. Cavalieri D, Parkinson C, Gloersen P, Zwally HJ (1996) Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data. National Snow and Ice Data Center. Digital media, Boulder (updated 2008)Google Scholar
  10. Cheng W, Bleck R, Rooth C (2004) Multi-decadal thermohaline variability in an ocean-atmosphere general circulation model. Clim Dyn 22:573–590Google Scholar
  11. Conkright ME, Locarnini RA, Garcia HE, OBrien TD, Boyer TP, Stephens C, Antonov JI (2002) World Ocean Atlas 2001: objective analyses, data statistics, and figures, CD-ROM documentation. National Oceanographic Data Center, Silver SpringGoogle Scholar
  12. Cunningham SA, Alderson SG, King BA, Brandon MA (2003) Transport and variability of the Antarctic circumpolar current in Drake passage. J Geophys Res 108(C5):8084. doi: 10.1029/2001JC001147 CrossRefGoogle Scholar
  13. Delworth TL, Greatbatch RJ (2000) Multidecadal thermohaline circulation variability driven by atmospheric surface flux forcing. J Clim 13:1481–1495CrossRefGoogle Scholar
  14. DeWeaver E, Bitz CM (2006) Atmospheric circulation and Its effect on Arctic Sea Ice in CCSM3 simulations at medium and high resolution. J Clim 19:2415–2436CrossRefGoogle Scholar
  15. Dickson R, Meincke J, Malmberg SA, Lee A (1988) The “great salinity anomaly” in the northern North Atlantic, 1968–1982. Progr Oceanogr 20:103–151CrossRefGoogle Scholar
  16. Dong S, Sprintall J, Gille ST, Talley L (2008) Southern ocean mixed-layer depth from Argo float profiles. J Geophys Res 113:C06013. doi: 10.1029/2006JC004051 CrossRefGoogle Scholar
  17. Dutra E, Balsamo G, Viterbo P, Miranda PMA, Beljaars A, Schär C, Elder K (2010) An improved snow scheme for the ECMWF land surface model: description and offline validation. J Hydrometeorol 11:899–916. doi: 10.1175/2010JHM1249.1 CrossRefGoogle Scholar
  18. ECMWF (2006) IFS documentation. Available at
  19. Fichefet T, Morales Maqueda MA (1997) Sensitivity of a global sea ice model to the treatment of ice thermodynamics and dynamics. J Geophys Res 102:12,609–12,646. doi: 10.1029/97JC00480 CrossRefGoogle Scholar
  20. Ganachaud A, Wunsch C (2000) Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature 408:453–457CrossRefGoogle Scholar
  21. Gent PR, McWilliams JC (1990) Isopycnal Mixing in Ocean Circulation Models. J Phys Oceanogr 20:150–155CrossRefGoogle Scholar
  22. Gibson JK, Kållberg P, Uppala S, Hernandez A, Nomura A, Serrano E (1997) ERA description. ECMWF reanalysis project report 1, ECMWF, Reading, UK, 72 ppGoogle Scholar
  23. Gnanadesikan A, Hallberg RW (2000) On the relationship of the circumpolar current to southern hemisphere winds in coarse-resolution ocean models. J Phys Oceanogr 30:2013–2034CrossRefGoogle Scholar
  24. Goosse H, Selten F, Haarsma R, Opstegh J (2002) A mechanism of decadal variability of the sea-ice volume in the Northern Hemisphere. Clim Dyn 19:61–83CrossRefGoogle Scholar
  25. Grist JP, Josey SA (2003) Inverse analysis adjustment of the SOC air-sea flux climatology using ocean heat transport constraints. J. Clim 20:3274–3295CrossRefGoogle Scholar
  26. Haak H, Jungclaus J, Mikolajewicz U, Latif M (2003) Formation and propagation of great salinity anomalies. Geophys Res Lett 30(9):26/1–126/4CrossRefGoogle Scholar
  27. Häkkinen S (1999) A simulation of thermohaline effects of a great salinity anomaly. J Clim 6:1781–1795CrossRefGoogle Scholar
  28. Hamilton P, Larsen JC, Leaman KD, Lee TN, E. Waddell E (2005) Transports through the Straits of Florida. J Phys Oceanogr 35:308–322CrossRefGoogle Scholar
  29. Hazeleger W, Severijns C, Semmler T, Ştefǎnescu S, Yang S, Wang X, Wyser K, Dutra E, Baldasano JM, Bintanja R, Bougeault P, Caballero R, Ekman AML, Christensen JH, van den Hurk B, Jimenez P, Jones C, Kållberg P, Koenigk T, McGrath R, Miranda P, van Noije T, Palmer T, Parodi JA, Schmith T, Selten F, Storelvmo T, Sterl A, Tapamo H, Vancoppenolle M, Viterbo P, Willén U (2010) EC-Earth: a seamless earth-system prediction approach in action. Bull Am Meteorol Soc 91:1357–1363. doi: 10.1175/2010BAMS2877.1 CrossRefGoogle Scholar
  30. Hazeleger W, Wang X, Severijns C, Ştefănescu S, Bintanja R, Sterl A, Wyser K, Semmler T, Yang S, Van den Hurk B, Van Noije T, Van der Linden E, Van den Wiel K (2011) EC-Earth V2: description and validation of a new seamless Earth system prediction model. Clim. Dyn. doi: 10.1007/s00382-011-1228-5
  31. Huang CJ, Qiao F, Song Z, Ezer T (2011) Improving simulations of the upper ocean by inclusion of surface waves in the Mellor-Yamada turbulence scheme. J Geophys Res 116:C01007. doi: 10.1029/2010JC006320 CrossRefGoogle Scholar
  32. Jungclaus JH, Haak H, Latif M, Mikolajewicz U (2005) Arctic-North Atlantic interactions and multidecadal variability of the meridional overturning circulation. J Clim 18:4013–4031CrossRefGoogle Scholar
  33. Kanzow T, Cunningham SA, Johns WE, Hirschi JJ-M, Marotzke J, Baringer MO, Meinen CS, Chidichimo MP, Atkinson C, Beal LM, Bryden HL, Collins J (2010) Seasonal variability of the Atlantic meridional overturning circulation at 26.5°N. J Clim 23:5678–5698. doi: 10.1175/2010JCLI3389.1 CrossRefGoogle Scholar
  34. Kaplan A, Cane M, Kushnir Y, Clement A, Blumenthal M, Rajagopalan B (1998) Analyses of global sea surface temperature 1856–1991. J Geophys Res 103:18567–18589CrossRefGoogle Scholar
  35. Koenigk T, Mikolajewicz U, Haak H, Jungclaus J (2006) Variability of Fram Strait sea ice export: causes, impacts and feedbacks in a coupled climate model. Clim Dyn 26:17–34. doi: 10.1007/s00382-005-0060-1 CrossRefGoogle Scholar
  36. Kwok R, Cunningham G, Pang S (2004) Fram Strait sea ice outflow. J Geophys Res 109:C01009. doi: 10.1029/2003JC001785 CrossRefGoogle Scholar
  37. Lavender K, Davis R, Owens W (2002) Observations of open-ocean deep convection in the Labrador Sea from subsurface floats. J Phys Oceanogr 32(2):511–526CrossRefGoogle Scholar
  38. Locarnini RA, Mishonov AV, Antonov JI, Boyer TP, Garcia HE, Baranova OK, Zweng MM, Johnson DR (2010) World Ocean Atlas 2009, volume 1: temperature. In: Levitus S (ed) NOAA Atlas NESDIS 68. U.S. Government Printing Office, Washington, DCGoogle Scholar
  39. Madec G (2008) NEMO ocean engine. Note du Pole de modélisation. Institut Pierre-Simon Laplace (IPSL), Paris, France, No 27 ISSN No 1288–1619Google Scholar
  40. Morawitz W, Sutton P, Worcester P, Cornuelle B, Lynch J, Pawlowitz R (1996) Three-dimensional observations of a deep convective chimney in the Greenland Sea during winter 1988/89. J Phys Oceanogr 26:2316–2343CrossRefGoogle Scholar
  41. Randall DA, Wood RA, Bony S, Colman R, Fichefet T, Fyfe J, Kattsov V, Pitman A, Shukla J, Srinivasan J, Stouffer RJ, Sumi A, Taylor KE (2007) Climate models and their evaluation. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, CambridgeGoogle Scholar
  42. Risien CM, Chelton DB (2008) A global climatology of surface wind and wind stress fields from eight years of QuikSCAT scatterometer data. J Phys Oceanogr 38:2379–2413CrossRefGoogle Scholar
  43. Rothrock DA, Zhang J, Yu Y (2003) The Arctic ice thickness anomaly of the 1990s: a consistent view from observations and models. J Geophys Res 108(C3):30–83. doi: 10.1029/2001JC001208 CrossRefGoogle Scholar
  44. Simmons A, Uppala S, Dee D, Kobayashi S (2007) ERA-Interim: new ECMWF reanalysis products from 1989 onwards. ECMWF Newsletter 110 (Winter 2006/07, 11 pp)Google Scholar
  45. Smith GC, Bretherton D, Gemmell A, Haines K, Mugford R, Stepanov V, Valdivieso M, Zuo H (2010) Ocean reanalysis studies in reading: reconstructing water mass variability and transports. Mercator Ocean Q Newslett 36:39–49Google Scholar
  46. Smith GC, Haines K, Kanzow T, Cunningham S (2010) Impact of hydrographic data assimilation on the modelled Atlantic meridional overturning circulation. Ocean Sci 6:761–774. doi: 10.5194/os-6-761-2010 CrossRefGoogle Scholar
  47. Sprintall J, Wijffels SE, Molcard R, Jaya I (2009) Direct estimates of the Indonesian Throughflow entering the Indian Ocean: 2004–2006. J Geophys Res 114:C07001. doi: 10.1029/2008JC005257 CrossRefGoogle Scholar
  48. Trenberth KE (1997) The definition of El Niño. Bull Am Meterol Soc 78:2771–2777CrossRefGoogle Scholar
  49. Trenberth KE, Caron JM (2001) Estimates of meridional atmosphere and ocean heat transports. J Clim 14:3433–3443CrossRefGoogle Scholar
  50. Tsimplis MN, Bryden HL (2000) Estimation of transports through the Strait of Gibraltar. Deep Sea Res A 47:2219–2242. doi: 10.1016/S0967-0637(00)00024-8 CrossRefGoogle Scholar
  51. Valcke S (2006) OASIS3 user guide (prism_2-5). CERFACS technical report TR/CMGC/06/73, PRISM Report No 3, Toulouse, France. 60 pp,
  52. Vancoppenolle M, Fichefet T, Goosse H, Bouillon S, König Beatty C, Morales Maqueda MA (2008) LIM3, an advanced sea-ice model for climate simulation and operational oceanography. Mercator Ocean Q Newslett 28:16–21Google Scholar
  53. Vellinga M, Wu P (2004) Low-latitude fresh water influence on centennial variability of the thermohaline circulation. J Clim 17:4498–4511CrossRefGoogle Scholar
  54. Vinje T (2001) Fram strait ice fluxes and atmospheric circulation: 1950–2000. J Clim 14:3508–3517CrossRefGoogle Scholar
  55. Wadhams P, Budeus G, Wilkinson J, Loyning T, Pavlov V (2004) The multi-year development of long-lived convective chimneys in the Greenland Sea. Geophys Res Lett 31:L06306. doi: 10.1029/2003GL019017 CrossRefGoogle Scholar
  56. Woodgate RA, Aagaard K, Weingartner TJ (2006) Interannual changes in the Bering Strait fluxes of volume, heat and freshwater between 1991 and 2004. Geophys Res Lett 33:L15609. doi: 10.1029/2006GL026931 CrossRefGoogle Scholar
  57. Worby AP, Geiger CA, Paget MJ, Van Woert ML, Ackley SF, DeLiberty TL (2008) Thickness distribution of Antarctic sea ice. J Geophys Res 113:C05S92. doi: 10.1029/2007JC004254 CrossRefGoogle Scholar
  58. Yaremchuk MI, Nechaev DA, Thompson KR (2001) Seasonal variation of the North Atlantic Current. J Geophys Res 106(C4):6835–6851CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Andreas Sterl
    • 1
    Email author
  • Richard Bintanja
    • 1
  • Laurent Brodeau
    • 2
  • Emily Gleeson
    • 3
  • Torben Koenigk
    • 4
  • Torben Schmith
    • 5
  • Tido Semmler
    • 3
  • Camiel Severijns
    • 1
  • Klaus Wyser
    • 4
  • Shuting Yang
    • 5
  1. 1.Royal Netherlands Meteorological Institute (KNMI) De BiltNetherlands
  2. 2.Department of MeteorologyStockholm UniversityStockholmSweden
  3. 3.Met ÉireannDublinIreland
  4. 4.Swedish Meteorological and Hydrological Institute (SMHI)NorrköpingSweden
  5. 5.Danish Meteorological Institute (DMI)CopenhagenDenmark

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