National Oceanic and
Atmospheric Administration
United States Department of Commerce


FY 2005

Global Ocean Data Analysis Project (GLODAP): Results and data

Sabine, C.L., R.M. Key, A. Kozyr, R.A. Feely, R. Wanninkhof, F.J. Millero, T.-H. Peng, J.L. Bullister, and K. Lee

ORNL/CDIAC-145, NDP-083, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, TN, 110 pp. plus 6 Appendices (2005)

During the 1990s, ocean sampling expeditions were carried out as part of the World Ocean Circulation Experiment, the Joint Global Ocean Flux Study, and the Ocean Atmosphere Carbon Exchange Study. Most of the cruises included various inorganic carbon species among the suite of routinely measured parameters. Both during and after the field work, a group of U.S. scientists collaborated to synthesize the data into easily usable and readily available products. This collaboration is known as the Global Ocean Data Analysis Project (GLODAP).

Both measured results and calculated quantities were merged into common-format data sets, segregated by ocean. The carbon data were subjected to rigorous secondary quality control procedures, beyond those typically performed on individual cruise data, to eliminate systematic biases in the basin-scale compilations. For comparison purposes, each ocean data set included results from a small number of high-quality historical cruises. The calibrated 1990s data were used to estimate anthropogenic CO2, potential alkalinity, chlorofluorocarbon (CFC) water mass ages, CFC partial pressure, bomb-produced radiocarbon, and natural radiocarbon. The calibrated-merged data were used to produce objectively gridded global property maps designed to match existing climatologies for temperature, salinity, oxygen, and nutrients. Both the data sets and the gridded products are available from the Carbon Dioxide Information Analysis Center (CDIAC). Here we summarize important details of the data assembly, calibration, calculations, and mapping.

The synthesis was carried out one ocean at a time, progressing from the Indian to the Pacific and ending with the Atlantic. The entire synthesis required about five years. During that period, new methods were developed and old ones modified. At the same time, the data set itself changed and expanded. Many of the GLODAP results are already published. Rather than repeat what is published, we concentrate here on summarizing important details of the data assembly and mapping. In particular, we focus on the procedural differences that evolved as the individual basin data sets were compiled and developments in the data set that have not been covered in the individual publications. Some of the GLODAP publications are attached as appendices.

The GLODAP data set described here (Gv1.1) is available free of charge as a numeric data package (NDP-83) from CDIAC. The data, and any subsequent updates, are also available through the GLODAP web site ( The GLODAP bottle data files are available in flat ASCII file data format, in Ocean Data View (ODV) format, and through the CDIAC live access server (LAS); the gridded data files are available in flat ASCII and NetCDF data file formats and through CDIAC LAS.

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