Table of Contents

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

   PI:              David Kirchman
   of:              University of Delaware (Lewes, Delaware)
   dataset:         Uptake of dissolved free amino acids, 15N uptake,
                    Thymidine production
   dates:           May 20, 1985 to May 28, 1985
   location:        N: 46.9  S: 46.2  W: -18.5  E: -19.9
   Project/cruise:  North Atlantic Bloom Experiment/Atlantis II 119, leg 5
   ship:            R/V Atlantis II

U.S. JGOFS North Atlantic Bloom Experiment (NABE)

Uptake of dissolved free amino acids, 15N uptake and Thymidine production

Prepared by U.S. JGOFS DMO for David Kirchman

N biomass and N uptake by heterotrophic bacteria and phytoplankton were examined during the North Atlantic spring blooom (May 18-31, 1989) aboard the R/V Atlantis II in the vicinity of 47 N, 20 W. The ship followed drifting sediment trap arrays and samples were usually obtained in the morning from CTD/30 litre Niskin rosette casts.

DMO note:
These data lack sufficient metadata to accurately determine sampling location. Data were only reported from a total of 3 sampling locations, and although there were several CTD/Rosette casts done during each of those three days, it is possible through process of elimination to determine the correct station number by matching sampling depths in the bottle data object from this cruise. There are two possible matches for the data reported from 1989-05-20, so the position is estimated from both possible station locations as 46.8333N and 18.347W.

In hopes of making these data more useful, the DMO added metadata to this data object in September 2009, to support geolocation of the data.

date      sta  cast  event     latitude longitude  sampling_activity
19890520  27   5     05200840  46.8333  -18.3467  CTD/Rosette_200m_N-15/micro
or
19890520  27   10    05201930  46.8333  -18.3483  CTD/Rosette_200m_N-15/micro
19890522  29   6     05221617  46.3650  -17.9333  CTD/rosette_1000m_del-N-15
19890528  35   4     05281115  46.3367  -17.8650  CTD/rosette_250m_N-15/micro

For a complete description of methodology, please refer to:
Kirchman, DL, HW Ducklow, JJ McCarthy and C Garside, 1994. Biomass and nitrogen
uptake by heterotrophic bacteria during the spring phytoplankton bloom in the
North Atlantic Ocean. Deep-Sea Research I, Vol.41. No.5/6, pp.879-895

Reference:
Kirchman, DL, HW Ducklow, JJ McCarthy and C Garside, 1994.  Biomass and nitrogen
uptake by heterotrophic bacteria during the spring phytoplankton bloom in the
North Atlantic Ocean.  Deep-Sea Research I, Vol.41. No.5/6, pp.879-895
 
Related data including measured values of heterotrophic bacteria uptake rates of
dissolved free amino acids and 15N, bacteria production measured by the thymidine
method, and a broad array of derived parameters are available as a
downloadable Excel spreadsheet file.
 
 

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).