Carbon dioxide, hydrographic, and chemical data obtained during the Thomas Washington Cruise TUNES-3 in the equatorial Pacific Ocean (WOCE Section P16C)

Abstract

This report discusses the procedures and methods used to obtain measurements of total carbon dioxide (TCO{sub 2}), total alkalinity (TALK), and radiocarbon ({Delta} {sup 14}C), as well as hydrographic and chemical data, during the Research Vessel Thomas Washington Expedition TUNES-1 in the Equatorial Pacific Ocean (Section P17C). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in San Diego, California, on May 31, 1991, and ended in Papeete, Tahiti, on July 11, 1991. WOCE Meridional Section P17C, along 135{degree}W and between {approximately}5{degree}S and 36{degree}N, was completed during the 42-day expedition. All 123 hydrographic stations (including 9 large-volume stations) were completed to the full water-column depth. Spacing between stations was 30 nautical miles, except between 3{degree}N and 3{degree}S, where it was 10 nautical miles. At 30 stations, CO{sub 2} measurements were provided for the US Department of Energy`s Carbon Dioxide Program. Hydrographic and chemical measurements made along WOCE Section P17C included pressure, temperature, salinity, and oxygen (measured by conductivity, temperature, and depth sensor), as well as bottle measurements of salinity, oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbon (CFC)-11, CFC-12, {Delta} {sup 14}C, TCO{sub 2}, and TALK. In addition, potential temperatures were calculated from the measured variables.