Ancillary data
In many instances, optical measurements are used as proxies for biogeochemical parameters (e.g. Chlorophyll a, POC, TSM, DOC, HPLC pigments, size distribution). Often, the proxies are of much wider utility than the IOPs themselves. While ‘global’ proxy relationships exist, it is highly desirable that biogeochemical measurements are made periodically along the cruise to establish the ‘cruise-specific’ relationships.