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European Marine Observation and Data Network (EMODnet)

Ocean Acidification

In recent decades, ocean acidification has been occurring 100 times faster than over the past 55 million years (European Environment Agency, 2020), thus threatening marine ecosystems with different pressures. For this reason, the ocean acidification is widely included in the European Integrated Maritime Policy.

EMODnet Chemistry gives a valuable scientific contribution to European environmental strategies, providing free and open access to data and data products on ocean acidification in seawater from all EU marine basins.

Currently more than 189,000 records and CDI metadata are stored. The number of records per group of variables is shown in the table below (updated to 30 June, 2022).

Group of variable No. of records
Alkalinity, acidity and pH of the water column 184854
Carbonate chemistry in sediment pore waters 285
Partial pressure (pCO2) and fugacity (fCO2) of carbon dioxide in the water column 256
Total dissolved inorganic carbon (TCO2) concentration in the water column 3877

The Measurement data, as delivered by the originators, are accessible through the CDI Data Discovery and Access Service:

The Service provides relevant metadata, including the identifier, data originator, and data holding centre for all datasets. Depending on the specific sharing policy (public, restricted, or moratorium) applied by the originator, data can be downloaded after user registration and a shopping request.

Data collections of standardised, harmonised and validated datasets are available for six sea regions, as shown in the figure below.

Ocean Acidification - Sea regions with available data collections
Ocean Acidification - Sea regions with available data collections

The data collection of each region is accessible through a digital object identifier. The aggregated data are available in the ODV csv spreadsheet format, which can be easily handled and visualised with the ODV Software. Multiple parameter codes (P01 terms) and associated standard units (P06 terms) are automatically aggregated and standardised using the EMODnet Chemistry P35 vocabulary .

All datasets have been subjected to a stepwise aggregation process. First, they were processed and validated using the ODV tools. Second, a data harmonisation and quality assessment was carried out for each region. The entire process is detailed in the guidelines.

The ocean acidification data collections are available on the Central Portal through the EMODnet Catalogue Service and through the external  webODV Data Explorer and Extractor service, which allows users to explore, visualise, and extract subsets of the data in a simple way using their web browser.

A clear and concise explanation of this ODV online tool is given in a dedicated video tutorial and the user manual .

The products can be freely used for non-commercial and educational purposes. However, the data in the maps have been homogenised and filtered to allow comparisons between countries. Therefore, EMODnet Chemistry’s visualisation products may not be comparable to source data accessible through other platforms.

EMODnet Chemistry is not responsible for the use of the data and products by third parties. Users are requested to give due credit to the EMODnet Chemistry project and the data originators.