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| HAL : hal-00672526, version 1 |
| DOI : 10.1029/2011GL049966 |
| Fiche détaillée |  Récupérer au format |
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| Geophysical Research Letters 39 (2012) L01606, |
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| North Pacific Gyre Oscillation modulates seasonal timing and ecosystem functioning in the California Current upwelling system |
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Fanny Chenillat 1Pascal Rivière 1 |
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| (14/01/2012) |
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| On interannual and longer time scales, dynamical and biogeochemical fluctuations in the North Pacific are dominated by two modes of variability, namely the Pacific Decadal Oscillation and the North Pacific Gyre Oscillation (NPGO). In this study the regional expression of the NPGO in the California Current System (CCS) is detailed. The statistical relationship between the NPGO index and nearshore wind variability (mostly upwelling favorable) along the U.S. West coast is strongest in the wintertime (December to March) off Central California. Most importantly, NPGO fluctuations are associated with a seasonal shift of 1-2 months in the onset of the upwelling season. Regional numerical simulations show that an early (late) onset of upwelling during the positive (negative) phase of the NPGO leads to a more (less) productive planktonic ecosystem throughout spring and summer, i.e., several months after the direct NPGO effects on the system have ceased. These results bring new light on the California ecosystem variability as observed in atypical years such as 2005 and 2007. |
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| 1 : | Laboratoire des Sciences de l'Environnement Marin (LEMAR) |
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Institut Universitaire Européen de la Mer (IUEM) – Université de Bretagne Occidentale - Brest – CNRS : UMR6539 – Institut de Recherche pour le Développement |
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| 2 : | Laboratoire de physique des océans (LPO) |
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CNRS : UMR6523 – Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) – INSU – Université de Bretagne Occidentale - Brest – IRD |
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| 3 : | School of Earth and Atmospheric Sciences |
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Georgia Institute of Technology |
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| Domaine | : | Sciences de l'environnement Planète et Univers/Sciences de la Terre/Océanographie |
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| California upwelling system – ecosystem – numerical modeling – seasonal variability |
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| Liste des fichiers attachés à ce document : | |||||
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| hal-00672526, version 1 | |
| http://hal.univ-brest.fr/hal-00672526 | |
| oai:hal.univ-brest.fr:hal-00672526 | |
| Contributeur : Dominique Gac | |
| Soumis le : Mardi 21 Février 2012, 14:11:49 | |
| Dernière modification le : Mardi 21 Février 2012, 15:22:37 | |
