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Climate Dynamics

, Volume 20, Issue 4, pp 381–399 | Cite as

The North Atlantic Oscillation in coupled climate models: a CMIP1 evaluation

  •  D. Stephenson
  •  V. Pavan
  • participating CMIP1 modelling groups

Abstract.

This study investigates the North Atlantic Oscillation (NAO) simulated by 17 global coupled ocean–atmosphere models participating in the Coupled Model Intercomparison Project (CMIP). Robust NAO indices are defined by calculating the leading principal components of winter time mean surface temperatures (land and sea) in the North Atlantic region (120°W–60°E, 20–80°N). Encouragingly, 13 out of 17 of the models capture the NAO surface temperature quadrupole pattern with centres of action over Northwest Europe, the northwest Atlantic, the southeastern USA, and the Middle East. The northern dipole is better captured than the southern dipole which is often simulated too far eastwards over the Atlantic Ocean. Out of the 17 models, ten models produce NAO indices that vary similar to the observations as stationary "weakly red noise" with only small correlations between successive winters (r < 0.3). Another five models drift monotonically towards warmer conditions, and two models exhibit long-term stochastic trends. Several of the models significantly overestimate the teleconnection between NAO and the tropical ENSO phenomenon.

Keywords

Middle East North Atlantic Oscillation Atmosphere Model North Atlantic Oscillation Index Warm Condition 
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.

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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  •  D. Stephenson
    • 1
  •  V. Pavan
    • 2
  • participating CMIP1 modelling groups
  1. 1.Department of Meteorology, University of Reading, PO Box 243, Earley Gate, Reading RG6 6BB, UK
  2. 2.ARPA-SMR, Viale Silvani 6, 40122 Bologna, Italy

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