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Publications, presentations and other activities
On the robustness of ENSO teleconnections
2007
by A. Sterl (KNMI), G.J. van Oldenborgh (KNMI), W. Hazeleger (KNMI), G. Burgers (KNMI),
Abstract
The El Niño-Southern Oscillation is known to have signifant teleconnections influencing the weather in large parts of the Globe. The strength of these teleconnections seems to change over time. Using observations covering the last 128 years we show that these apparent changes can be explained by chance, stemming from sampling variability. This result is backed by experiments in which an atmosphere model is driven by 123 years of observed sea surface temperature. The possibility of ENSO teleconnection changes in a warming climate is further investigated using coupled GCMs driven by past and projected future greenhouse gas concentrations. These runs do not exclude physical changes in the teleconnection strength but do not agree on their magnitude and location. If existing at all, changes in the strength of ENSO teleconnection, other than obtained by chance, are small and will only be detectable on centennial time scales.
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Correlation between the NINO3.4 index and SLP in January for (a) observations (HadSLP1/HadISST_1_1), (b) reanalysis (ERA-40), (c) SPEEDY, and (d) ECHAM5/MPI-OM1. Model results are for the whole ensemble (members concatenated), and only the historical period (before 2000) is used for (c) and (d) for better comparison with (a) and (b). Superimposed as black contours is the significance of changes in the strength of the correlations (contours between 0.9 and 1 in steps of 0.01).
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Biblographic data
| Sterl, A., G.J. van Oldenborgh, W. Hazeleger and G. Burgers, On the robustness of ENSO teleconnections Abstract (html) Complete text (pdf: 6 MB) |  |
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