Kilometric Scale Modeling of the North West European Shelf Seas: Exploring the Spatial and Temporal Variability of Internal Tides

• Autores: Guihou, Karen; Polton, J.; Harle, J.; Wakelin, S.; O'Dea, E.; Holt, J.
• Año de publicación: 2018
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: HIGH-RESOLUTION MODELING; INTERNAL TIDES; NORTH-WESTERN EUROPEAN SHELF; OBSERVATIONS
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The North West European Shelf break acts as a barrier to the transport and exchange between the open ocean and the shelf seas. The strong spatial variability of these exchange processes is hard to fully explore using observations, and simulations generally are too coarse to simulate the fine-scale processes over the whole region. In this context, under the FASTNEt program, a new NEMO configuration of the North West European Shelf and Atlantic Margin at 1/60° (∼1.8 km) has been developed, with the objective to better understand and quantify the seasonal and interannual variability of shelf break processes. The capability of this configuration to reproduce the seasonal cycle in SST, the barotropic tide, and fine-resolution temperature profiles is assessed against a basin-scale (1/12°, ∼9 km) configuration and a standard regional configuration (7 km resolution). The seasonal cycle is well reproduced in all configurations though the fine-resolution allows the simulation of smaller scale processes. Time series of temperature at various locations on the shelf show the presence of internal waves with a strong spatiotemporal variability. Spectral analysis of the internal waves reveals peaks at the diurnal, semidiurnal, inertial, and quarter-diurnal bands, which are only realistically reproduced in the new configuration. Tidally induced pycnocline variability is diagnosed in the model and shown to vary with the spring neap cycle with mean displacement amplitudes in excess of 2 m for 30% of the stratified domain. With sufficiently fine resolution, internal tides are shown to be generated at numerous bathymetric features resulting in a complex pycnocline displacement superposition pattern.
Fil: Guihou, Karen. National Oceanography Centre; Reino Unido. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Polton, J.. National Oceanography Centre; Reino Unido
Fil: Harle, J.. National Oceanography Centre; Reino Unido
Fil: Wakelin, S.. National Oceanography Centre; Reino Unido
Fil: O'Dea, E.. Met Office; Reino Unido
Fil: Holt, J.. National Oceanography Centre; Reino Unido