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.

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.

The Global Sea Level Observing System (GLOSS) was established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO in 1985 to establish a well-designed, high-quality in situ sea level observing network to support a broad research and operational user base. Various tide gauge networks have contributed to GLOSS, each with a different focus and each changing over time as research priorities evolve. The main component is the GLOSS Core Network (GCN), a global set of ~300 tide gauges that serves as the backbone of the global in situ sea level network. GCN gauges were allocated to each island or group of islands at intervals not closer than 500 km, and along continental coasts at intervals generally not less than 1000 km. Preference was given to islands in order to maximise exposure to the open ocean. Established in 1933, the Permanent Service for Mean Sea Level (PSMSL) is responsible for the collection, publication, analysis and interpretation of sea level data from the global network of tide gauges, including the GLOSS Core Network.

VOS/SOOP tracks are usually repeated several times a year and inform about the marine sinks and sources of atmospheric carbon dioxide on a global bases and their variability. Data from this network has been made available to the scientific community and interested public via the Carbon Dioxide Information Analysis Centre (CDIAC) Oceans at the Department of Energy, USA, since the early 1990’s where PIs submitted and shared their data. In 2017, CDIAC Ocean will be named Ocean Carbon Data System (OCADS) and join NOAA’s National Centers for Environmental Information (NCEI). In 2007, the marine biogeochemistry community coordinated by the International Ocean Carbon Coordination Project (IOCCP), launched the Surface Ocean Carbon Dioxide ATlas (SOCAT) in order to uniformly quality control and format the data with detailed documentation. Underway carbon dioxide data from the VOS network are integrated in SOCAT.

The Drifting Buoys GDAC -Global Data Assembly Centre- is the repository of surface drifters data. Both NRT -Near Real Time- and DM -Delayed Mode- data are available on the GDAC. Drifters report generally trajectories, sea-surface temperatures, atmospheric pressures at sea-level, as well as sea-surface salinity or sub-surface temperature in the ocean top layer.

ICES database of trawl surveys

The Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology Observing Programmes Support Centre, provides technical coordination at international level for the sustained elements of the Global Ocean Observing System. The Centre monitors in real-time the status of the observing networks and provides a toolbox to evaluate their performance and optimize their implementation and data flow. Currently OceanOPS monitors the Argo profiling floats, the DBCP surface drifters, coastal and tropical moorings, ice buoys, tsunami buoys, the OceanSITES moorings time-series, the GO-SHIP hydrographic reference lines, the SOT mat/ocean ship based observations and the GLOSS sea level tide gauges. A number of other observing systems are being added gradually, including ocean gliders, polar systems, marine mammals and potentially HF radars.

The Sir Alister Hardy Foundation for Ocean Science (SAHFOS) is an international charity that operates the Continuous Plankton Recorder (CPR) Survey. The dataset covers the North Atlantic and the North Sea on since 1958.

ICES hosts data collected from both net trawl surveys (primarily bottom trawling), and from echo sounding (acoustic sampling in the pelagic zone). The net trawls are primarily hosted in the DATRAS data portal, and the acoustics in the acoustic trawl surveys portal. DATRAS (the Database of Trawl Surveys) stores data collected primarily from bottom trawl fish surveys coordinated by ICES expert groups. The survey data are covering the Baltic Sea, Skagerrak, Kattegat, North Sea, English Channel, Celtic Sea, Irish Sea, Bay of Biscay and the eastern Atlantic from the Shetlands to Gibraltar. At present, there are more than 45 years of continuous time series data in DATRAS, and survey data are continuously updated by national institutions. The acoustic database hosts information on fisheries observations collected from various pelagic surveys coordinated by ICES and falls into two categories: acoustic data, derived from readings taken on vessels, and those obtained through trawls in the open ocean – pelagic – zone. Combined, this provides key biological data on fish stocks such as herring, mackerel and blue whiting as well as krill and other prey species. The data from both systems are used for stock assessments and fish community studies by the ICES community and form the basis of management advice to the relevant regulatory bodies.

The European Ocean Biogeographic Information System - EurOBIS - is an online marine biogeographic database compiling data on all living marine creatures. The principle aims of EurOBIS are to centralize the largely scattered biogeographic data on marine species collected by European institutions and to make these data freely available and easily accessible. All data go through a number of quality control procedures before they are made available online, assuring a minimum level of quality necessary to put the data to good use. The available data are either collected within European marine waters or by European researchers and institutes outside Europe. The database focuses on taxonomy and distribution records in space and time; all data can be searched and visualised through a set of online mapping tools. All data are freely available online and easily accessible, without requiring a login or password.