Ocean pH level

The Ocean Ph Level index is relevant to marine ecosystems. This Index is part of the Biochemical ocean properties type of the Oceanic category of the classification. A higher/lower index value indicates higher/lower acidity and thus lower/higher risk. Today, ocean water is normally slightly basic, with a surface-water pH of about 8.1.

Definition

The Ocean pH Level index (dimensionless) is the seawater pH at a certain depth. pH is a measure of the concentration of hydrogen ions in a solution. The more hydrogen ions that are present, the more acidic is the solution. The pH scale ranges from zero (very acidic) to 14 (very basic). The scale is logarithmic, meaning a single unit corresponds to a ten-fold difference. A pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic.

Data Sources

The simulated index data are from the Marine biogeochemistry data for the Northwest European Shelf and Mediterranean Sea from 2006 up to 2100 derived from climate projections dataset. The dataset contains a set of projected changes in marine physics and biogeochemical variables used to infer climate change indicators, as well as changes in the lower trophic levels (plankton) of the marine food web. Two sets of simulations were produced with the ERSEM ecosystem model coupled with two circulation models (POLCOMS and NEMO) over two different domains (pan european for POLCOMS or northwest european shelf for NEMO) and time frames from 2006 up to 2049 (NEMO-ERSEM) or 2099 (POLCOMS-ERSEM). Here only the data from POLCOMS-ERSEM is used as it covers a larger domain over a longer time frame. The spatial resolution is 1° x 1° (approximately 11kmx11km) with 43 vertical layers and covers the 2006-2099 period and both RCP4.5 and RCP8.5.

Supporting Information

Further information about this application can be found in the ECDE application User Guide and the Data and datasets underpining the ECDE. Related information can also be found on other sections of the EEA site: The Index based interactive EEA report: Open ocean — ocean chemistry: dissolved oxygen and ocean acidity (link).

Data download

The aggregated data shown on the map can be downloaded as csv files.