CCHDO: Tall Tales from decades of reuniting global repeat hydrographic data

Stephen C Diggs1, Karen I Stocks2, Carolina Berys-Gonzales2, Andrew Barna1, Jerry Kappa2,3, Lynne Merchant4 and James H Swift3,5, (1)Scripps Institution of Oceanography / UC San Diego, La Jolla, United States, (2)Scripps Institution of Oceanography, La Jolla, CA, United States, (3)UCSD/SIO, La Jolla, CA, United States, (4)Scripps Institution of Oceanography, La Jolla, United States, (5)University of California San Diego, La Jolla, CA, United States
The mission of CCHDO is to aggregate and disseminate the highest quality CTD, hydrographic, carbon and tracer data. These data come from vessel-based expeditions repeatedly sampling the same cruise tracks. While each expedition has limited coverage, CCHDO provides a central access point for global data, allowing large-scale research questions to be addressed. And with data going back ~50 years, questions of long-term patterns and trends can also be investigated. Cornerstones of the CCHDO approach include: staff with deep expertise with these data and their collection methods, strict quality requirements, and meticulous assembly of the data into data products provided in several standard formats. And we do not forget the human element: ongoing relationships and communications with the scientists providing the data ensures more data are shared, and quality issues are addressed by the experts.

CCHDO is moving towards increased interoperability with other ocean data repositories through current and planned efforts to: provide all data in an NetCDF-CF compliant data format, implement dataset-level markup for improved discovery, and allow profile-level as well as cruise-level data searching and download. These steps will also make CCHDO data more accessible and usable for multidisciplinary projects, such as ocean modelling, satellite ground-truthing, and coupled ocean-atmosphere research.