Thorium 234, POC and biogenic silica from R/V Melville, USCGC Polar Star cruises COOK19MV, PS02_2002 from the Southern Ocean, south of New Zealand in 2002 (SOFeX project)

Website: https://www.bco-dmo.org/dataset/2927
Version: 18 April 2007
Version Date: 2007-04-18

Project
» Southern Ocean Iron Experiment (SOFeX)

Programs
» Ocean Carbon and Biogeochemistry (OCB)
» Iron Synthesis (FeSynth)
ContributorsAffiliationRole
Buesseler, Kenneth O.Woods Hole Oceanographic Institution (WHOI)Principal Investigator
Chandler, Cynthia L.Woods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

Thorium 234, POC and biogenic silica from the 2002 SOFeX project South Patch experiment


 dates:           29 January 2002 to 20 February 2002  (20020129-20020220) 
 location:        N: -65.25  S: -66.91  W: -172.99  E: -170.60 
 project/cruise:  SOFeX/MV and SOFeX/PS
 platform:        SOFeX multi-ship: R/V Melville and USCGC Polar Star
 
 
 Methodology: Buesseler, et al. 2005

    "Particle export during the Southern Ocean Iron Experiment (SOFeX)". Limnol. 
    Oceanogr., 50(1). American Society of Limnology and Oceanography, Inc. pp.311-327. 
 
 Change history: YYMMDD 
    070323: data contributed by Ken Buesseler as emailed PDF file
    070418: added to OCB database by Cyndy Chandler, OCB DMO, (cchandler@whoi.edu) 
 
 PI note: POC blank greater than 75% for 50-100 m in patch POC_gt54 observations
    on 9 and 11 February 2002

In the data set, bd indicates observed value is 'below detection'.


Methods & Sampling

 Methodology: Buesseler, et al. 2005

    "Particle export during the Southern Ocean Iron Experiment (SOFeX)". Limnol. 
    Oceanogr., 50(1). American Society of Limnology and Oceanography, Inc. pp.311-327. 
 
 PI note: POC blank greater than 75% for 50-100 m in patch POC_gt54 observations
    on 9 and 11 February 2002

In the data set, bd indicates observed value is 'below detection'.


Data Processing Description

 Change history: YYMMDD 
    070323: data contributed by Ken Buesseler as emailed PDF file
    070418: added to OCB database by Cyndy Chandler, OCB DMO, (cchandler@whoi.edu) 

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Data Files

File
thorium.csv
(Comma Separated Values (.csv), 4.67 KB)
MD5:2e5277d02f77a20937cf09c07c2f7b27
Primary data file for dataset ID 2927

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Parameters

ParameterDescriptionUnits
patch_loc

sampling location relative to patch

dimensionless
depth_r

depth range

dimensionless
lat

latitude, negative denotes South

decimal degrees
lon

longitude, negative denotes West

decimal degrees
date

date sampling began (UTC)

YYYYMMDD
time

time sampling began (UTC)

hhmm
depth

depth of sample

meters
Th234_gt54

Thorium 234 greater than 54 micro m

dpm per liter
Th_gt54_err

Thorium 234 gt54 error

dpm per liter
Th234_lt54

Thorium 234 less than 54 micro m

dpm per liter
Th234_lt54_err

Thorium 234 lt54 error

dpm per liter
POC_gt54

POC greater than 54 micro m

micromolar
POC_gt54_err

POC gt 54 error

micromolar
POC_lt54

POC less than 54 micro m

micromolar
C_to_N

carbon to nitrogen ratio gt 54 um

molar
POC_Th_gt54

POC to Thorium ratio gt 54 um

micromol per dpm
POC_Th_gt54_err

POC to Thorium ratio gt 54 um, error

micromol per dpm
POC_Th_lt54

POC to Thorium ratio lt 54 um

micromol per dpm
bSiO2_gt54

biogenic silica greater than 54 um

micromolar
bSiO2_Th

biogenic silica to Thorium ratio greater than 54 micro m

micromol per dpm

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Deployments

COOK19MV

Website
Platform
R/V Melville
Report
Start Date
2002-01-19
End Date
2002-02-26
Description
Brief cruise plan description: Three ships were involved in the SOFeX experiment. Each ship operated in the study area at a different time to afford the longest observation time. The designations SOFeX-N and SOFeX-S are sometimes used to distinguish between two iron enriched patches - one in low silicate waters north of the polar front (SOFEX-N), and the other in high silicate waters south of the polar front (SOFEX-S). All three ships, Melville (MV), Revelle (RR) and Polar Star (PS), worked in SOFEX-S, but only the Revelle and Melville worked in the SOFeX N patch and shuttled between the two patches. The R/V MELVILLE sailed several weeks after the R/V REVELLE to arrive in the study area just as the 'patches' were forming in response to iron fertilization. The MELVILLE's team planned to make detailed measurements of phytoplankton physiology and rate processes, and to sample daily for phytoplankton growth rates and biomass, soluble and particulate iron and zooplankton biomass. A cruise logbook includes daily entries filed by the Chief Scientist aboard each vessel.

Methods & Sampling
Methodology: Buesseler, et al. 2005 "Particle export during the Southern Ocean Iron Experiment (SOFeX)". Limnol. Oceanogr., 50(1). American Society of Limnology and Oceanography, Inc. pp.311-327. PI note: POC blank greater than 75% for 50-100 m in patch POC_gt54 observations on 9 and 11 February 2002 In the data set, bd indicates observed value is 'below detection'.

Processing Description
Change history: YYMMDD 070323: data contributed by Ken Buesseler as emailed http://ocb.whoi.edu/SOFeX/PI-NOTES/data_orig/0311a2.pdf">PDF file 070418: added to OCB database by Cyndy Chandler, OCB DMO, (cchandler@whoi.edu)

PS02_2002

Website
Platform
USCGC Polar Star
Report
Start Date
2002-02-11
End Date
2002-02-21
Description
Cruise dates provided by David Forcucci, USCG Science Liaison Brief cruise plan description: Three ships were involved in the SOFeX experiment. Each ship operated in the study area at a different time to afford the longest observation time. The designations SOFeX-N and SOFeX-S are sometimes used to distinguish between two iron enriched patches - one in low silicate waters north of the polar front (SOFEX-N), and the other in high silicate waters south of the polar front (SOFEX-S). All three ships, Melville (MV), Revelle (RR) and Polar Star (PS), worked in SOFEX-S, but only the Revelle and Melville worked in the SOFeX N patch and shuttled between the two patches. The USCGC Polar Star was the third of the three vessels to occupy the SOFeX study area in 2002. The main focus of the scientific party aboard the Polar Star was to assess how much carbon was removed from the iron fertilized patches. The cruise report includes a more complete description of the Polar Star cruise and a cruise logbook includes daily entries filed by the Chief Scientist aboard each vessel.

Methods & Sampling
Methodology: Buesseler, et al. 2005 "Particle export during the Southern Ocean Iron Experiment (SOFeX)". Limnol. Oceanogr., 50(1). American Society of Limnology and Oceanography, Inc. pp.311-327. PI note: POC blank greater than 75% for 50-100 m in patch POC_gt54 observations on 9 and 11 February 2002 In the data set, bd indicates observed value is 'below detection'.

Processing Description
Change history: YYMMDD 070323: data contributed by Ken Buesseler as emailed http://ocb.whoi.edu/SOFeX/PI-NOTES/data_orig/0311a2.pdf">PDF file 070418: added to OCB database by Cyndy Chandler, OCB DMO, (cchandler@whoi.edu)


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Project Information

Southern Ocean Iron Experiment (SOFeX)


Coverage: Southern Ocean, south of New Zealand


Before he passed away in 1993, John Martin suggested that an increase in the flow of iron-rich dust to the ocean causes phytoplankton (single celled algae) to grow. The increased photosynthesis removes carbon dioxide from surface waters as the algae create biomass. This carbon dioxide is replaced by carbon dioxide gas that flows into the sea from the atmosphere. Reduced carbon dioxide in the atmosphere cools the planet (CO2 is a greenhouse gas that warms the earth). The results of this work, funded by the National Science Foundation, the Department of Energy, and the US Coast Guard, will be a much better understanding of how biological processes may regulate climate. (see Related Info: Fe cycle)

A direct test of the 'Martin Hypothesis' that trace concentrations of Fe are responsible for phytoplankton's ability to grow by direct experimental addition of Fe to the surface waters. Consequently the distribution of bioavailable Fe in the surface waters determines large geographical areas primary production and the following flux of fixed organic matter to the deep sea. The aim of the SOFeX project is to investigate the effects of iron fertilization on the productivity of the Southern Ocean. The results of this work will contribute significantly to our understanding of important biogeochemical processes which bear directly on the global carbon cycle, atmospheric carbon dioxide concentration, and climate control.

The SOFeX-N and SOFeX-S designations are sometimes used to distinguish between two iron enriched patches - one in low silicate waters north of the polar front (SOFEX-N), and the other in high silicate waters south of the polar front (SOFEX-S). All three ships, Melville (MV), Revelle (RR) and Polar Star (PS), worked in SOFEX-S, but only the Revelle and Melville worked in the SOFeX N patch and shuttled between the two patches.



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Program Information

Ocean Carbon and Biogeochemistry (OCB)


Coverage: Global


The Ocean Carbon and Biogeochemistry (OCB) program focuses on the ocean's role as a component of the global Earth system, bringing together research in geochemistry, ocean physics, and ecology that inform on and advance our understanding of ocean biogeochemistry. The overall program goals are to promote, plan, and coordinate collaborative, multidisciplinary research opportunities within the U.S. research community and with international partners. Important OCB-related activities currently include: the Ocean Carbon and Climate Change (OCCC) and the North American Carbon Program (NACP); U.S. contributions to IMBER, SOLAS, CARBOOCEAN; and numerous U.S. single-investigator and medium-size research projects funded by U.S. federal agencies including NASA, NOAA, and NSF.

The scientific mission of OCB is to study the evolving role of the ocean in the global carbon cycle, in the face of environmental variability and change through studies of marine biogeochemical cycles and associated ecosystems.

The overarching OCB science themes include improved understanding and prediction of: 1) oceanic uptake and release of atmospheric CO2 and other greenhouse gases and 2) environmental sensitivities of biogeochemical cycles, marine ecosystems, and interactions between the two.

The OCB Research Priorities (updated January 2012) include: ocean acidification; terrestrial/coastal carbon fluxes and exchanges; climate sensitivities of and change in ecosystem structure and associated impacts on biogeochemical cycles; mesopelagic ecological and biogeochemical interactions; benthic-pelagic feedbacks on biogeochemical cycles; ocean carbon uptake and storage; and expanding low-oxygen conditions in the coastal and open oceans.


Iron Synthesis (FeSynth)

Coverage: Global


The two main objectives of the Iron Synthesis program (SCOR Working Group proposal, 2005), are:
1. Data compilation: assembling a common open-access database of the in situ iron experiments, beginning with the first period (1993-2002; Ironex-1, Ironex-2, SOIREE, EisenEx, SEEDS-1; SOFeX, SERIES) where primary articles have already been published, to be followed by the 2004 experiments where primary articles are now in progress (EIFEX, SEEDS-2; SAGE, FeeP); similarly for the natural fertilizations S.O.JGOFS (1992), CROZEX (2004/2005) and KEOPS (2005).

2. Modeling and data synthesis of specific aspects of two or more such experiments for various topics such as physical mixing, phytoplankton productivity, overall ecosystem functioning, iron chemistry, CO2 budgeting, nutrient uptake ratios, DMS(P) processes, and combinations of these variables and processes.

SCOR Working Group proposal, 2005. "The Legacy of in situ Iron Enrichments: Data Compilation and Modeling".
http://www.scor-int.org/Working_Groups/wg131.htm

See also: SCOR Proceedings Vol. 42 Concepcion, Chile October 2006, pgs: 13-16 2.3.3 Working Group on The Legacy of in situ Iron Enrichments: Data Compilation and Modeling.

The first objective of the Iron Synthesis program involves a data recovery effort aimed at assembling a common, open-access database of data and metadata from a series of in-situ ocean iron fertilization experiments conducted between 1993 and 2005. Initially, funding for this effort is being provided by the Scientific Committee on Oceanic Research (SCOR) and the U.S. National Science Foundation (NSF).

Through the combined efforts of the principal investigators of the individual projects and the staff of Biological and Chemical Oceanography Data Management Office (BCO-DMO), data currently available primarily through individuals, disparate reports and data agencies, and in multiple formats, are being collected and prepared for addition to the BCO-DMO database from which they will be freely available to the community.

As data are contributed to the BCO-DMO office, they are organized into four overlapping categories:
1. Level 1, basic metadata
(e.g., description of project/study, general location, PI(s), participants);
2. Level 2, detailed metadata and basic shipboard data and routine ship's operations
(e.g., CTDs, underway measurements, sampling event logs);
3. Level 3, detailed metadata and data from specialized observations
(e.g., discrete observations, experimental results, rate measurements) and
4. Level 4, remaining datasets
(e.g., highest level of detailed data available from each study).

Collaboration with BCO-DMO staff began in March of 2008 and initial efforts have been directed toward basic project descriptions, levels 1 and 2 metadata and basic data, with detailed and more detailed data files being incorporated as they become available and are processed.

Related file

Program Documentation

The Iron Synthesis Program is funded jointly by the Scientific Committee on Oceanic Research (SCOR) and the U.S. National Science Foundation (NSF).



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