Climate Dynamics

, Volume 39, Issue 11, pp 2631–2657

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


    • Royal Netherlands Meteorological Institute (KNMI)
  • Richard Bintanja
    • Royal Netherlands Meteorological Institute (KNMI)
  • Laurent Brodeau
    • Department of MeteorologyStockholm University
  • Emily Gleeson
    • Met Éireann
  • Torben Koenigk
    • Swedish Meteorological and Hydrological Institute (SMHI)
  • Torben Schmith
    • Danish Meteorological Institute (DMI)
  • Tido Semmler
    • Met Éireann
  • Camiel Severijns
    • Royal Netherlands Meteorological Institute (KNMI)
  • Klaus Wyser
    • Swedish Meteorological and Hydrological Institute (SMHI)
  • Shuting Yang
    • Danish Meteorological Institute (DMI)

DOI: 10.1007/s00382-011-1239-2

Cite this article as:
Sterl, A., Bintanja, R., Brodeau, L. et al. Clim Dyn (2012) 39: 2631. doi:10.1007/s00382-011-1239-2


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 modelNEMO ocean model: general ocean circulationSurface fluxesSea iceOcean heat transport

Supplementary material

$$ F = F^{\ast}, $$$$ F = \sum_i f_i A_i, $$$$ F^{\ast} = \sum_j f^{\ast}_j A^{\ast}_j. $$$$ F = \sum_i \sum_t \alpha_{i,t} f_{i,t} A_i, $$$$ F^{\ast} = \sum_j \sum_t \alpha^{\ast}_{j,t} f^{\ast}_{j,t} A^{\ast}_j. $$$$ F = \sum_t \sum_i \alpha_{i,t} f_{i,t} A_i, $$$$ F^{\ast} = \sum_t \sum_j \alpha^{\ast}_{j,t} f^{\ast}_{j,t} A^{\ast}_j. $$$$ \sum_i \alpha_{i,t} f_{i,t} A_i = \sum_j \alpha^{\ast}_{j,t} f^{\ast}_{j,t} A^{\ast}_j. $$$$ \sum_i \alpha_{i,t} f_{i,t} A_i w_{i,j} = \alpha^{\ast}_{j,t} f^{\ast}_{j,t} A^{\ast}_j, $$$$ \alpha_{i,t} \rightarrow \alpha^{\ast}_{j,t}, $$$$ \alpha_{i,t} f_{i,t} \rightarrow (\alpha_{j,t} f_{j,t})^{\ast} \equiv \alpha^{\ast}_{j,t} f^{\ast}_{j,t}, $$$$ f^{\ast}_{j,t} = (\alpha_{j,t} f_{j,t})^{\ast} / \alpha^{\ast}_{j,t}. $$

Copyright information

© Springer-Verlag 2011