This gridded product visualizes 1960 - 2014 water body ammonium concentration (umol/l) in the North Sea domain, for each season (winter: December – February; spring: March – May; summer: June – August; autumn: September – November). It is produced as a Diva 4D analysis, version 4.6.9: a reference field of all seasonal data between 1960-2014 was used; results were logit transformed to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. Every step of the time dimension corresponds to a 10-year moving average for each season. The depth dimension allows visualizing the gridded field at various depths.

This gridded product visualizes 1960 - 2014 water body silicate concentration (umol/l) in the North Sea domain, for each season (winter: December – February; spring: March – May; summer: June – August; autumn: September – November). It is produced as a Diva 4D analysis, version 4.6.9: a reference field of all seasonal data between 1960-2014 was used; results were logit transformed to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. Every step of the time dimension corresponds to a 10-year moving average for each season. The depth dimension allows visualizing the gridded field at various depths.

Combined product of Water body ammonium based on DIVA 4D 10-year analysis on five regions : Northeast Atlantic Ocean, North Sea, Baltic Sea, Black Sea, Mediterranean Sea. The boundaries and overlapping zones between these five regions were filtered to avoid any unrealistic spatial discontinuities. This combined Water body ammonium product is masked using the relative error threshold 0.5. Units: umol/l.

Combined product of Water body phosphate based on DIVA 4D 10-year analysis on five regions : Northeast Atlantic Ocean, North Sea, Baltic Sea, Black Sea, Mediterranean Sea. The boundaries and overlapping zones between these five regions were filtered to avoid any unrealistic spatial discontinuities. This combined water body phosphate product is masked using the relative error threshold 0.5. Units: umol/l

The data collection of the North Sea is divided in two datasets : the discrete collection and the trajectories collection. The Discrete SeaDataCloud Temperature and Salinity Historical Data Collection for the North Sea includes open access in situ data on temperature and salinity measured with “discrete” instruments (CTD, XBT, discrete water samplers…). The data span between 4°W and 10°E in longitude, and from 49°N to 62°N in latitude. It covers the time period 1893 – 2017. The data were retrieved from the SeaDataNet infrastructure in November 2017. The “Trajectories” SeaDataCloud Temperature and Salinity Historical Data Collection for the North Sea includes open access in situ data on temperature and salinity measured by continuously recording sensors (e.g. Ferryboxes). The data span between 4°W and 10°E in longitude, and from 49°N to 62°N in latitude. It covers the time period 1989 – 2017. The data were retrieved from the SeaDataNet infrastructure in November 2017. The quality control of the data has been performed with the help of ODV software. Data Quality Flags have been revised following common recommended procedures defined under SeaDataNet 2 project in conjunction with visual expert check. The dataset format is ODV binary collections. You can read, analyse and export from the ODV application provided by Alfred Wegener institute at http://odv.awi.de/. For data access please register at http://www.marine-id.org/.

The analysis was performed per season using DIVA software tool (Data-Interpolating Variational Analysis). The analyses products are stored as NetCDF CF files and made available as WMS layers for easy browsing and adding. Every step of the time dimension corresponds to a 6-year moving average from 1983 to 2016. The depth dimension spans from surface to 1000 m, with 21 vertical levels. The boundaries and overlapping zones between these regions were filtered to avoid any unrealistic spatial discontinuities. This combined water body dissolved oxygen concentration product is masked using the relative error threshold 0.5. Units: µmol/l Created by 'University of Liège, GeoHydrodynamics and Environment Research (ULiège-GHER)'. The data used as input for DIVA have been extracted from the EMODnet Chemistry Download Service: https://emodnet-chemistry.maris.nl/search Intermediate regional data products: Mediterranean Sea - DIVA 4D 6-year analysis of Water body silicate 1965/2016 v2018 https://doi.org/10.6092/bb4fa82c-7731-4b1d-9cde-a031ca83e40c Arctic Ocean - DIVA 4D 6-year analysis of Water body silicate 1980/2017 v2018 https://doi.org/10.6092/3ebe4a8b-9ecb-4e00-b617-47576d49dc29 North Sea - DIVA 4D 6-year analysis of Water body silicate 1980/2017 v2018 https://doi.org/10.6092/62eebfd8-f97f-4e28-9e2e-9677a3b165ad Black Sea - DIVA 4D 6-year analysis of Water body silicate 1990/2016 v2018 https://doi.org/10.6092/9521c33f-d8d1-4576-b184-6651c1c0145b North East Atlantic Ocean - DIVA 4D 6-year analysis of Water body silicate 1971/2017 v2018 https://doi.org/10.6092/468fc3aa-139d-450f-afe2-a0dc81953533

Combined product of Water body chlorophyll a based on DIVA 4D 10-year analysis on five regions : Northeast Atlantic Ocean, North Sea, Baltic Sea, Black Sea, Mediterranean Sea. The boundaries and overlapping zones between these five regions were filtered to avoid any unrealistic spatial discontinuities. This combined Water body chlorophyll a product is masked using the relative error threshold 0.5. Units: mg/m^3. Created by 'University of Liege, GeoHydrodynamics and Environment Research (ULg-GHER)'.

The analysis was performed per season using DIVA software tool (Data-Interpolating Variational Analysis). The analyses products are stored as NetCDF CF files and made available as WMS layers for easy browsing and adding. Every step of the time dimension corresponds to a 6-year moving average from 1983 to 2016. The depth dimension spans from surface to 1000 m, with 21 vertical levels. The boundaries and overlapping zones between these regions were filtered to avoid any unrealistic spatial discontinuities. This combined water body dissolved oxygen concentration product is masked using the relative error threshold 0.5. Units: µmol/l Created by 'University of Liège, GeoHydrodynamics and Environment Research (ULiège-GHER)'. The data used as input for DIVA have been extracted from the EMODnet Chemistry Download Service: https://emodnet-chemistry.maris.nl/search Intermediate regional data products: Mediterranean Sea - DIVA 4D 6-year analysis of Water body chlorophyll-a 1990/2017 v2018 https://doi.org/10.6092/5346c32c-acd3-4534-800a-7947f5914315 Arctic Ocean - DIVA 4D 6-year analysis of Water body chlorophyll-a 1980/2017 v2018 https://doi.org/10.6092/28a025c3-1f79-4f6d-b71a-86641e2b7346 Black Sea - DIVA 4D 6-year analysis of Water body chlorophyll-a 1990/2016 v2018 https://doi.org/10.6092/3da98812-0b51-40ca-a95b-3f43de243c74 North East Atlantic Ocean - DIVA 4D 6-year analysis of Water body chlorophyll-a 1960/2017 v2018 https://doi.org/10.6092/ce474bda-7eba-11e8-84a3-40a8f051e8d0 North Sea - DIVA 4D 6-year analysis of Water body chlorophyll-a 1980/2017 v2018 https://doi.org/10.6092/d0e36bce-91d2-4baf-996d-2be3e16164f1 Baltic Sea - DIVA 4D 6-year analysis of Water body chlorophyll-a 1980/2016 v2018 https://doi.org/10.6092/66dcf80f-383c-4c70-842a-80eead8bd293

The analysis was performed per season using DIVA software tool (Data-Interpolating Variational Analysis). The analyses products are stored as NetCDF CF files and made available as WMS layers for easy browsing and adding. Every step of the time dimension corresponds to a 6-year moving average from 1983 to 2016. The depth dimension spans from surface to 1000 m, with 21 vertical levels. The boundaries and overlapping zones between these regions were filtered to avoid any unrealistic spatial discontinuities. This combined water body dissolved oxygen concentration product is masked using the relative error threshold 0.5. Units: µmol/l Created by 'University of Liège, GeoHydrodynamics and Environment Research (ULiège-GHER)'. The data used as input for DIVA have been extracted from the EMODnet Chemistry Download Service: https://emodnet-chemistry.maris.nl/search Intermediate regional data products: Mediterranean Sea - DIVA 4D 6-year analysis of Water body phosphate 1968/2016 v2018 https://doi.org/10.6092/165371b0-d5d3-4188-bf20-74b139cf5e4b Arctic Ocean - DIVA 4D 6-year analysis of Water body phosphate 1980/2017 v2018 https://doi.org/10.6092/d0618e05-bc9b-4212-9aa3-12eb2a6b8756 North Sea - DIVA 4D 6-year analysis of Water body phosphate 1980/2017 v2018 https://doi.org/10.6092/61170426-61e4-40c0-b45b-7e23fa1dbe84 Black Sea - DIVA 4D 6-year analysis of Water body phosphate 1990/2016 v2018 https://doi.org/10.6092/dfe8bcc1-4d97-4962-9857-d3f8e0ce1fc6 North East Atlantic Ocean - DIVA 4D 6-year analysis of Water body phosphate 1960/2017 v2018 https://doi.org/10.6092/54a52f81-d8bf-457f-aee3-d48a25645727 Baltic Sea - DIVA 4D 6-year analysis of Water body phosphate 1980/2016 v2018 https://doi.org/10.6092/e5bfc6fd-f287-4e1d-81ae-6af0ea3f1eef

Combined product of Water body dissolved oxygen concentration based on DIVA 4D 10-year analysis on five regions : Northeast Atlantic Ocean, North Sea, Baltic Sea, Black Sea, Mediterranean Sea. The boundaries and overlapping zones between these five regions were filtered to avoid any unrealistic spatial discontinuities. This combined water body dissolved oxygen concentration product is masked using the relative error threshold 0.5. Units: umol/l