This document presents the reults of surface water and atmospheric carbon dioxide (CO2) and nitrous oxide (N2O) measurements carried out by shipboard gas chromatography over the period 1977-1990. These data include results from 11 different oceanic surveys for a total of 41 expedition legs. Collectively, they represent a globally distributed sampling that includes locations in the Atlantic, Pacific, Indian, and Southern Oceans, as well as the Mediterranean and Red Seas.

The measurements were made by an automated high-precision shipboard gas chromatographic system developed during the late 1970s and used extensively over the intervening years. This instrument measures CO2 by flame ionization after quantitative reaction to methane in a stream of hydrogen. Nitrous oxide is measured by a separate electron capture detector. the chromatographic system measures 196 dry-gas samples a day, divided equally among the atmosphere, gas equilibrated with surface water, a low-range gas standard, and a high-range gas standard.

These data constitute one of the most extensive records available of CO2 and, particularly, N2O in marine air and surface seawater. the data will be valuable in modeling applications dealing with the ocean's role in the global cycles of carbon and nitrogen, in studies of ocean-atmosphere dynamics, and in studies evaluating other methodologies for determining pCO2

All data have been assesssed for quality and consistency and have been edited to remove serious outliers and contaminated samples and to correct gross numerical errors.

These data are available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center (CDIAC). The NDP consists of this document and a magnetic tape (or set of floppy diskettes) containing machine-readable files.α This document provides sample listings of the surface water and atmospheric CO2 and N2O data, offers retrieval program listings (in FORTRAN and SASβ languages), furnishes graphical and tabular information on each of the contributing oceanic expeditions, defines limitations and restrictions of the data, and reprints pertinent literature.


  • R. F. WEISS, F. A. VAN WOY, AND P. K. SALAMEH. 1992. Surface water and atmospheric carbon dioxide and nitrous oxide observations by shipboard automated gas chromatography: Results from expeditions between 1977 and 1990. Scripps Institution of Oceanography Reference 92-11. ORNL/CDIAC-59, NDP-044. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennesse. 144 pp. doi: 10.3334/CDIAC/otg.ndp044

αFiles are also available through Internet using the File Transfer Protocol (FTP) from CDIAC&aposs anonymous FTP area.
βSAS is the registered trademark of SAS Institute, Inc., Cary, NC 27511-8000.

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