GLODAP

Cruises conducted as part of the World Ocean Circulation Experiment (WOCE), Joint Global Ocean Flux Study (JGOFS), and the NOAA Ocean-Atmosphere Exchange Study (OACES) over the decade of the 1990s created an oceanographic database of unparalleled quality and quantity. These data provide an important asset to the scientific community investigating carbon cycling in the oceans. The central objective of this five year project was to generate a unified data set to help determine the global distributions of both natural and anthropogenic inorganic carbon, including radiocarbon. These estimates provide an important benchmark against which future observational studies will be compared. They also provide tools for the direct evaluation of numerical ocean carbon models.

Over approximately an 8-year period (1990–1998) the global CO₂ survey produced over 15 times more high-quality carbon measurements than had previous survey efforts. These data were collected on more than 100 individual cruises by more than a dozen different analytical laboratories. For these data to be useful for evaluating global-scale issues (e.g., the oceanic inventory of anthropogenic CO₂) they had to be unified into an internally consistent data set. Wherever possible, we tried to include survey data from parallel international survey programs. The international data were extremely important for filling in ocean regions not covered by the U.S. cruises. The final result is a data set with more than 12,000 oceanographic stations with 353,042 unique samples. We have put a great deal of effort into evaluating the quality of the survey data and recommending adjustments where necessary. The evaluations were conducted at the basin scale starting with the Indian Ocean, then the Pacific, and finally the Atlantic. The results of this extensive data compilation and evaluation are presented in NDP-083.

For those preferring to work with a regular 3-D data set instead of the irregularly spaced shipboard measurements, we have generated a global gridded carbon data product . The gridded procedure and additional information are described in Key, R.M., A. Kozyr, C.L. Sabine, K. Lee, R. Wanninkhof, J.L. Bullister, R.A. Feely, F.J. Millero, and T.-H. Peng, A global ocean carbon climatology: Results from GLODAP. Global Biogeochem. Cycles, 18, GB4031, doi:10.1029/2004GB002247, 2004.