The SeaDataNet aggregated datasets over the Atlantic Ocean are regional ODV historical collections of all temperature and salinity measurements contained within SeaDataNet database and covering 3 European sea basins: North Arctic Ocean, North Sea, North Atlantic Ocean. Two versions have been published during SeaDataNet 2 and they represent a snapshot of the SeaDataNet database content at two different times: • V1.1 January 2014 • V2 March 2015 Each of them is the result of the Quality Check Strategy (QCS) implemented during SeaDataNet 2 that contributed to highly improve the quality of temperature and salinity data. The QCS is made by four main phases: 1. data harvesting from the central CDI 2. file and parameter aggregation 3. quality check analysis at regional level 4. analysis and correction of data anomalies. The aggregated datasets have been prepared and quality checked using ODV software.

Shom uses HYCOM 3D (Hybrid Coordinate Ocean Model) digital models to model changes to the ocean environment (currents, temperature, salinity, water depth). These HYCOM 3D models include a scalable (space and time) vertical grid, which is particularly suitable for the coastal regions and physical phenomena modelled (particularly the transition from a deep sea zone to the continental shelf, and the presence of frontal zones). These models were adapted to coastal models at Shom, particularly by integrating tides and the effects of rivers. These models focus on changes and variability in the different physical processes affecting coastal areas (continental shelves and slopes), such as tidal fronts, river plumes, tides and internal waves, upwelling and the dynamics of the mixed layer at an hourly frequency and with high spatial resolution (1/60 deg for the Biscay Channel model).

SeaDataNet gridded climatologies are based on the SeaDataNet Temperature and Salinity historical data collection v1.1. For the Atlantic Ocean there are covering 2 European sea basins: North Arctic Ocean, and North Atlantic Ocean The preparation of the products has also improved the quality, the consistency and the overall coherence of the data made available by SeaDataNet. They have been computed using DIVA software.

This annual statistics at 500m horizontal resolution was produced from the archived time series of MARS 3D physics model hindcast runs along French Atlantic Coast. The variable that is available here is Temperature. Values are expressed in Celsius degrees. In each pixel the value is an average of the values of the 40 vertical levels that are considered in the model.

The LAgrangian Transport EXperiment (LATEX) project (2008-2011) is designed to study the mechanisms of formation of anticyclonic eddies and their influence on cross-shelf exchanges in the western part of the GoL. The dynamics of mesoscale eddies is particularly important in this part of the GoL since it represents a key region for regulating the outflow from the continental shelf. The eddy dynamics is investigated using Symphonie, a 3-dimensional, primitive equation model, with a free sea surface, hybrid sigma coordinates, based on Boussinesq and hydrostatic approximations [Marsaleix et al., 2006, 2008]. We use the upwind-type advection-diffusion scheme adapted by Hu et al. [2009] to improve the ability of the model to reproduce coastal mesoscale eddies in the western part of the GoL. In the present study, the model is implemented over the whole GoL with an horizontal resolution of 1 km × 1 km (Figure 1). The vertical discretization consists of 40-hybrid vertical levels. The vertical resolution varies from 1 m in the upper ocean to 40 m near the bottom. "For a complete review of the LATEX projet, see : - Petrenko, A., A., Doglioli, A.M., Nencioli, F., Kersalé, M., Hu, Z., d'Ovidio, F. (2017). A review of the LATEX project: mesoscale to submesoscale processes in a coastal environment. Ocean Dynam., 67:513 - doi: 10.1007/s10236-017-1040-9 - https://doi.org/10.1007/s10236-017-1040-9 ----- Le projet LAgrangian Transport EXperiment (LATEX) (2008-2011) est conçu pour étudier les mécanismes de formation des tourbillons anticycloniques et leur influence sur les échanges entre plateaux dans la partie occidentale du GdL. La dynamique des tourbillons à méso-échelle est particulièrement importante dans cette partie du GdL, car elle représente une région clé pour la régulation du flux sortant du plateau continental. La dynamique des tourbillons est étudiée à l'aide de Symphonie, un modèle d'équation primitive tridimensionnel, avec une surface de mer libre, des coordonnées sigma hybrides, basé sur Boussinesq et des approximations hydrostatiques [Marsaleix et al., 2006, 2008]. Nous utilisons le schéma d'advection-diffusion de type vent debout adapté par Hu et al [2009] pour améliorer la capacité du modèle à reproduire les tourbillons côtiers à méso-échelle dans la partie occidentale du GdL. Dans la présente étude, le modèle est mis en œuvre sur l'ensemble du GdL avec une résolution horizontale de 1 km × 1 km (Figure 1). La discrétisation verticale est constituée de 40 niveaux verticaux hybrides. La résolution verticale varie de 1 m dans la partie supérieure de l'océan à 40 m près du fond. Pour plus d'information sur le projet LATEX : - Petrenko, A., A., Doglioli, A.M., Nencioli, F., Kersalé, M., Hu, Z., d'Ovidio, F. (2017). A review of the LATEX project: mesoscale to submesoscale processes in a coastal environment. Ocean Dynam., 67:513 - doi:10.1007/s10236-017-1040-9 - https://doi.org/10.1007/s10236-017-1040-9

This annual statistics at 500m horizontal resolution was produced from the archived time series of MARS 3D physics model hindcast runs along French Atlantic Coast. The variable that is available here is the Temperature. Values are expressed in Celcius degrees. The vertical level is the seabed.

This raster dataset represents the Sea Surface Temperature (SST) anomalies, i.e. changes of sea temperatures, in the European Seas. The dataset is based on the map "Mean annual sea surface temperature trend in European seas" by Istituto Nazionale di Geofisica e Vulcanologia (INGV), which depicts the linear trend in sea surface temperature (in °C/yr) for the European seas over the past 25 years (1989-2013). Since all changes of sea temperatures can be considered to have an impact on the marine environment, the pressure layer includes absolute values of SST anomalies, i.e. negative/decreasing temperature trends were changed to positive values so that they represent a pressure. The original data was in a 1° grid format but was converted to a 100 km resolution, adapted to the EEA 10 km grid and clipped with the area of interest. This dataset has been prepared for the calculation of the combined effect index, produced for the ETC/ICM Report 4/2019 "Multiple pressures and their combined effects in Europe's seas" available on: https://www.eionet.europa.eu/etcs/etc-icm/etc-icm-report-4-2019-multiple-pressures-and-their-combined-effects-in-europes-seas-1.