Quality Control of Biogeochemical Measurements, Version 7,1.

Abstract

An important step within CMEMS is to harmonize existing quality control and quality assurance procedures of the different areas involved. As the Copernicus service is thought to be available at any time and open to anyone, an agreement in good QC methods and procedures is vital to guarantee high data quality distributed to users via international exchange. The agreement on the implementation of uniform QC procedures has the potential to overcome the non- consistency within the existing datasets provided by the international community. The detection of anomalous values of biogeochemical (BGC) parameters is challenging due to their inherent high spatial and temporal variability, e.g., diel Chl a fluorescence can vary by an order of magnitude or more due to changes in irradiance, self-shading, physiological states, community composition and cloud cover (Huot and Babin, 2010). In fact, the phytoplankton community composition can change the diel variability with as much as a factor 4. It is therefore a challenge to define regional tests to check data quality in sea regions that have different characteristics. The amount of data available for building regional climatology of BGC parameters is also very limited due to historically fewer observations. The lack of a common reference database for these parameters makes it difficult to identify anomalies at regional level.