Table of Contents

• Dataset Description
  • Methods & Sampling
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

   PI:              Ken Buesseler
   of:              Woods Hole Oceanographic Institution
   dataset:         Thorium 234 activity in particulate and dissolved phases
   dates:           April 19, 1989 to June 5, 1989
   location:        N: 46.8317  S: 46.24  W: -18.3717  E: -17.68
   project/cruise:  North Atlantic Bloom Experiment/Atlantis II 119, leg 4 and 5
   ship:            R/V Atlantis II
 

Methodology:

Comments:
Data collected via in-situ pumping and gamma counting techniques referenced in:

Livingston, H.D. and J.K. Cochran (1987) Determination of transuranic and
thorium isotopes in ocean water in solution and in filterable particles.
J. Radioanal. Nucl. Chem., vol. 115 (2), 299-308.

Buesseler, K.O., M.P. Bacon, J.K. Cochran and H.D. Livingston (1990)
Shipboard measurement of Th-234 during the JGOFS Spring Bloom Experiment.
EOS, vol. 71 (2), 139.

All data decay corrected to mid-point of sampling time
Contacts: Ken O. Buesseler, Michael P. Bacon, Hugh D. Livingston (WHOI)
and J. Kirk Cochran (SUNY)

Data:
Thorium-234 activities reported as Dpm/l (disintegration per minute per liter)
Data for dissolved and particulate (0.5 micron nominal pore size) 234-Th
reported with a one sigma error. This error is propagated from errors
due to counting statistics, standardization and in-situ pump collection
efficiency.

A data quality code is assigned to each measurement.
a = Highest confidence level (ie. lowest error);
c = Poorest confidence level

This quality code is determined by a combination of sampling
and analytical factors, and is included in the reported error
estimate.

One of the first major activities of JGOFS was a multinational pilot project, North Atlantic Bloom Experiment (NABE), carried out along longitude 20° West in 1989 through 1991. The United States participated in 1989 only, with the April deployment of two sediment trap arrays at 48° and 34° North. Three process-oriented cruises where conducted, April through July 1989, from R/V Atlantis II and R/V Endeavor focusing on sites at 46° and 59° North. Coordination of the NABE process-study cruises was supported by NSF-OCE award # 8814229. Ancillary sea surface mapping and AXBT profiling data were collected from NASA's P3 aircraft for a series of one day flights, April through June 1989.

A detailed description of NABE and the initial synthesis of the complete program data collection efforts appear in: Topical Studies in Oceanography, JGOFS: The North Atlantic Bloom Experiment (1993), Deep-Sea Research II, Volume 40 No. 1/2.

The U.S. JGOFS Data management office compiled a preliminary NABE data report of U.S. activities: Slagle, R. and G. Heimerdinger, 1991. U.S. Joint Global Ocean Flux Study, North Atlantic Bloom Experiment, Process Study Data Report P-1, April-July 1989. NODC/U.S. JGOFS Data Management Office, Woods Hole Oceanographic Institution, 315 pp. (out of print).

The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.

The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).