Observation data for the total chlorophyll used to create maps and calculate the difference to the model output is taken from the OCCCI version 5 monthly climatology data.
Observation values for nutrients (phosphate, nitrates, and silica) are determined by calculating a global average from the World Ocean Atlas 2018 annual datasets. These datasets are also used for creating the observation maps and calculating the difference to the model output.
Observation values for pCO2 are calculated from an ensemble mean of the data-products from the Global Carbon Budget 2022. This data is also used for creating the observation map for dpCO2 and calculating the difference to the model output.
Observation data for the physics tracers used to create maps and calculate the difference to the model output is taken from the World Ocean Atlas 2018 annual datasets. We use the dataset for the period 2005-2018 for our comparison.
