U.S. measurement standards for the ocean carbon and repeat hydrography program adhere to or exceed those set by WOCE and JGOFS for CTD, hydrographic properties and carbon system components.
The U.S. teams encourage comparison studies of international scope.
To provide the opportunity for comparison with historical data, measurement techniques should be consistent with techniques used to collect the existing data unless there is significant scientific justification for change. When new techniques are adopted, methods for relating the new data to existing data should be developed. This requirement extends to regional comparisons as well.
As many measurements as possible should be made relative to a certified reference material standard. Such standards now exist for salinity, inorganic nutrients, dissolved inorganic carbon, total alkalinity and CFCs. Standards for other Level 1/2 measurements are urgently needed, based on experience in WOCE and JGOFS, for example, improved standardization of oxygen analysis procedures.