The CLIVAR and Carbon Hydrographic Data Office (CCHDO) is the repository, assembly center, and distribution center for global ocean CTD, hydrographic, carbon, and tracer data of the highest quality and utility. CCHDO adds value to the global observing system by ensuring that these data are curated, preserved, well-described, findable, accessible, and usable. This reduces the time to science and enlarges the user base for these data by creating standard, well-described data products.
The CCHDO currently curates data from over 2,500 cruises from 29 countries, an investment on the order of $1B in ship time. It is the official data center for CTD and water sample profile data from the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP), a key component of both the Global Climate Observing System and the Global Ocean Observing System.
The coast-to-coast, top-to-bottom, reference-quality ocean transects curated by the CCHDO provide a keystone in assessing and understanding the extent and nature of ocean changes. They are used to monitor the ocean storage and transport of heat, freshwater, carbon and nutrients; assess the ocean’s uptake of anthropogenic carbon and heat; monitor changes in ocean oxygen and acidification; and evaluate ocean circulation and ventilation. A principal scientific use of CCHDO data is model initiation, calibration and validation. Further, it provides critical reference data for Argo float calibration and quality control.
The CCHDO ensures that these valuable data and their associated documentation are (i) readily available for immediate research and education, (ii) easily accessible through several search and download sites aimed at diverse audiences, (iii) fed into global climatologies such as the World Ocean Atlas, GLODAP, GO-SHIP easy ocean, and the Argo reference climatology, (iv) supplied for climate assessments; and (v) in partnership with NOAA, archived for long-term preservation. Beyond simple accessibility, the CCHDO undertakes meticulous verification, assembly, and documentation, to produce standardized, well-described, reference-quality cruise data products from heterogeneous data submissions. The goal is to maximize data usability for the scientific community and ensure a long service life.