Chemistry

Data & products on marine water quality

Data Validation and Integration

Data quality

The network of data centres engaged in EMODnet Chemistry gathers marine chemistry datasets, both from marine environmental monitoring and scientific research. The data gathering is done in direct communication with data originators to ensure the best sets of measurement data and related metadata, and to prevent duplicates. Data originators are responsible for the first quality control of data and flagging with quality information.

As further step, a Quality Control (QC) loop is implemented to harmonize, standardize and validate data and metadata at European scale for marine litter and at regional scale for eutrophication, ocean acidification and contaminants. Data are extracted from the network of data centers into global data collections. The QC loop implies multiple validation steps as shown below:

Data are aggregated by grouping different analytic terms used by data originators into a unique agreed term with a unique measurement unit (e.g. ml/l for oxygen, umol/l for nitrate), and further quality controls are performed at regional level following a common approach.
A set of quality controls (QC) are applied and the results are communicated to the data providers to correct errors or anomalies in the original data. This feedback loop guarantees consistency among comprehensive databases, which include data from different sources, periods and geographic areas.
For eutrophication, ocean acidification and contaminants, the original measurement datasets are automatically harvested in six different European regions: Arctic Ocean, Baltic Sea, North Sea, Northeast Atlantic Ocean, Black Sea, and Mediterranean Sea. Resulting collections are aggregated and quality controlled by using ODV Software and the methodology illustrated above.

Regional coordinators of data collections for eutrophication, ocean acidification and contaminants.

Each regional data collection is accessible through a digital object identifier (DOI) and is described in the Catalogue service where users can also browse, search and download the related data products.

The National Institute for Ocean Science (IFREMER) is leader of the marine litter data collections, supported by the National Institute of Oceanography and Applied Geophysics (OGS).

Marine litter data collections: beach litter (on the left) and seafloor litter (on the right)