An Ocean-Wide DIC-13 Data Set

TitleAn Ocean-Wide DIC-13 Data Set
Publication TypeConference Paper
Year of Publication2000
AuthorsMcNichol, AP, Quay, PD, Stuart, DR, Sonnerup, RE, Key, RM
Conference Name2000 Ocean Sciences Meeting, San Antonio, TX (USA), 24-28 Jan 2000
Date PublishedJanuary 2000
PublisherAmerican Geophysical Union, 2000 Florida Ave., N.W. Washington, DC 20009 USA
Keywordscarbon cycling, Carbon dioxide, Deep water, dissolved inorganic carbon, ISW, Indian Ocean, Marine, Mass Spectrometry, Ocean circulation, Phosphates, PS, Antarctic Ocean, Q2 09146:TSD distribution, water masses and circulation, Stable isotopes, Standardization, Water masses, World Ocean, World Ocean Circulation Experiment (WOCE)

High quality DIC-13 measurements were made throughout the world's oceans at the University of Washington (UW) and the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility during both the OACES and WOCE programs. We are currently merging these two data sets which represent 25000 individual DIC- 13 measurements from 1260 stations. We will present the inter-laboratory calibration and standardization data. Based on 135 measurements on CO2 gas extracted at UW, the mean offset between the two labs is 0.01 o/oo, similar to the offset observed from an exchange of DIC standards (0.012 o/oo). Stations measured by both laboratories will also be examined for offsets, although one comparison in the Indian Ocean shows no significant differences. We will present our progress towards a global atlas of DIC-13, primarily maps of the merged data sets in the Pacific, Southern, and Indian Oceans. In this poster we will concentrate on regions that have been under-sampled in the past, e.g. the Southern Ocean. Additionally, we will examine the relationship of DIC-13 to PO4 and to DIC-14. A preliminary analysis of DIC-13 and PO4 from three WOCE lines in the Pacific indicates that the expected relationship is observed in the deep waters and that the data from different water masses occupy well-defined regions of the graph. We are examining the potential for using the relationship between DIC-14 and DIC-13 to improve our understanding of the penetration of bomb radiocarbon into the ocean as well as fundamental processes in the deep ocean. The relationship is complex yet the data from shallow to intermediate depths (100 to 1000m) follow two distinct parallel lines that are related to the hemisphere in which