About Intercalibration

Intercalibration as a means of producing consistent and comparable global datasets has been a high priority in GEOTRACES from the beginning.

Protocols for sampling and analysis were developed early to ensure consistent data quality. The recommendations are summarised in the GEOTRACES cookbook, a valuable resource in many questions of sea water analysis.

The initially participating labs performed intercalibration exercises in order to ensure consistent analytical quality, published in L&O Methods. Newly joining labs can build on these efforts by intercalibrating with already intercalibrated labs. New exercises are being conducted as new parameters are added to GEOTRACES.

Elemental co-ordinators provide expertise on certain groups of analytes, often by providing reference (or consensus) materials, assisting with intercalibrating a lab, or as contact points for newly joining groups.

Also reference seawater materials are available at no charge (click here for further details).

In addition to the general intercalibration of labs, all individual cruise data in GEOTRACES data products need to be intercalibrated with values from a crossover cruise following the intercalibration procedures, or following our defined alternative procedures. All TEI datasets going into a GEOTRACES data product have been assessed by the Standards and Intercalibration Committee, based on the intercalibration report. The flow chart below illustrates how the S&I assess data quality for IDP.

Many useful resources have been produced as part of GEOTRACES. Also, please explore the resources available on the menu “S&I” in the main menu bar.

Figure: Data quality assessment for IDP flow chart. Please click here to view it larger.
It is also possible to download it (as PDF file) here.