FY 2003

Carbon dioxide, hydrographic, and chemical data obtained during the R/V Knorr cruises 147-2, 151-2, 151-3, and 151-4 in the north Atlantic Ocean on WOCE sections AR24 (Nov. 2–Dec. 5, 1996) and A24, A20, and A22 (May 30–Sept. 3, 1997)

Johnson, K.M., R.M. Key, F.J. Millero, C.L. Sabine, D.W.R Wallace, C.D. Winn, L. Arlen, K. Erickson, K. Friis, Meridith Galanter, J. Goen, R. Rotter, C. Thomas, R. Wilke, T. Takahashi, and S.C. Sutherland

ORNL/CDIAC-143, NDP-082, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, TN, 34 pp (2003)

This documentation describes the procedures and methods used to measure total carbon dioxide (TCO2) total alkalinity (TALK), and partial pressure of CO (pCO) at hydrographic stations on the North Atlantic Ocean sections AR24, A24, A20, and A22 taken during the R/V Knorr Cruises 147-2, 151-2, 151-3, and 151-4 in 1996 and 1997. Conducted as part of the World Ocean Circulation Experiment (WOCE), the expeditions began at Woods Hole, Massachusetts, on October 24, 1996, and ended at Woods Hole on September 3, 1997. Instructions for accessing the data are provided.

A total of 5,614 water samples were analyzed for discrete TCO2 using two single-operator multiparameter metabolic analyzers (SOMMAs) coupled to a coulometer for extracting and detecting CO. The overall accuracy of the TCO determination was ± 1.59 µmol/kg. The TALK was determined in a total of 6,088 discrete samples on all sections by potentiometric titration using an automated titration system developed at the University of Miami. The accuracy of the TALK determination was ± 3 µmol/kg. A total of 2,465 discrete water samples were collected for determination of pCO in sea water on sections A24, A20, and A22. The pCO was measured by means of an equilibrator-IR system by scientists from Lamont-Doherty Earth Observatory. The precision of the measurements was estimated to be about ± 0.15%, based on the reproducibility of the replicate equilibrations on a single hydrographic station.

The North Atlantic data set is available as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of 12 ASCII data files, one Ocean Data View-formatted data file, a NDP-082 ASCII text file, a NDP-082 PDF file, and this printed documentation, which describes the contents and format of all files, as well as the procedures and methods used to obtain the data.