Abstract
Two consecutive multidisciplinary surveys, covering the north and north-western part of the Iberian shelf and slope during spring 2000, showed a dramatic change in the oceanographic conditions as a result of a southern water intrusion that replaced shelf and slope waters down to 300 m depth. The intrusion covered an alongshore distance of ∼400 km from the north of Cape Finisterre to the centre of the Cantabrian Sea, and was developed in less than a month between the two occupations of the same area. The analysis of surface currents from several buoys moored over the slope allow us to associate the emerging oceanographic configuration after the event with a strong and well-defined slope current, although during winter 1999–2000 the entrance of the Iberian Poleward Current (IPC) in the Bay of Biscay was very weak. The rapid development of the intrusion is discussed in relation with the unusual strong wind forcing pulse that occurred between the cruises. Our results highlight the importance of variability scales below seasonal (event-scale) in the Iberian margin.
Acknowledgements
The SEAMAR project was funded through the Commission of the European Communities (FAIR CT98-3695), Comisión Interministerial de Ciencia y Tecnología (Spain, EC 97/0097), and Instituto Español de Oceanografía. We would like to thank all those who helped with this project, especially the crew of the different oceanographic surveys. The analysis of these data set has been performed in relationship with projects PLATERIAS (PGIDIT03TAM60401PR, financed by the Dirección Xeral de Investigación e Desenvolvemento, Consellería de Innovación, Industria e Comercio, Xunta de Galicia, Spain and IEO) and VACLAN (REN2003-08193-C03-01/MAR). We deeply acknowledge all different organizations who provided data and products used in this study: NOAA-CIRES Climate Diagnostics Center (www.cdc.noaa.gov), AVISO group (www.aviso.oceanobs.com), NCAR Climate analysis section (www.cgd.ucar.edu) and Spanish Meterological Service (www.inm.es). Finally, we wish to thank the valuable comments of two anonymous referees.