Table of Contents

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

SOIREE Vertical Fe GoFlo Data

During the cruise we had the following three objectives:
(1) Undertake continuous sampling of the infused patch for dissolved/total iron
(2) Obtain samples from vertical profiles, using Go-Flo bottles, to examine the
partitioning between dissolved and particulate iron within the water column, both
inside and outside the patch.
(3) Undertake measurements to determine iron speciation within the water column.

Go-Flo casts were taken both inside and outside the patch during the course
of the experiment. Typically, water samples were obtained from four standard
depths (20, 40, 60 and 80 m) throughout the water column at each station. Deeper
samples (> 80 m) were obtained at some stations to examine the concentration of
iron below the mixed layer. Both filtered (0.2 um) and unfiltered samples were
collected. These samples will be analysed for Fe and other trace metals (Zn, Cd, Mn, Cu)
back in the clean laboratory at the University of Otago.

The speciation of iron was measured using competitive ligand exchange cathodic stripping
voltammetry (CLE CSV) on samples from 40 m depth from stations both inside and outside the
patch. This technique determines the total concentration of iron binding ligands present
in the sample and their relative binding strengths. From the data generated an estimation
of the inorganic iron concentration, Fe`, can also be made, this value can be used to
approximate the amount of iron that may be available for uptake by the phytoplankton.

References
Bowie, A.R., Maldonado, M.T., Frew, R.D., Croot P.L., Achterberg, E.A., Mantoura, R.F.C.,
Worsfold, P.J., Law, C.S., Boyd P.W., The Fate of Added Iron during a Mesoscale Fertilisation
Experiment in the Southern Ocean, Deep-Sea Research II (2001), SOIREE special issue, in the press.

Bruland, K.W., Franks, R.P., Knauer, G.A., Martin, J.H., 1979. Sampling and analytical methods for
the determination of copper, cadmium, zinc and nickel at the nanogram per litre level in seawater.
Analytica Chimica Acta 105, 233-245.

Danielsson, L.G., Magnusson, B., Westerlund, S., Zhang, K., 1982. Trace-metal determinations
in estuarine waters by electrothermal atomic-absorption spectrometry after extraction of
dithiocarbamate complexes into freon. Analytica Chimica Acta 144, 183-188.

See SOIREE Preliminary Voyage Report

Go-Flo casts were taken both inside and outside the patch during the course

of the experiment. Typically, water samples were obtained from four standard

depths (20, 40, 60 and 80 m) throughout the water column at each station. Deeper

samples (> 80 m) were obtained at some stations to examine the concentration of

iron below the mixed layer. Both filtered (0.2 um) and unfiltered samples were

collected. These samples will be analysed for Fe and other trace metals (Zn, Cd, Mn, Cu)

back in the clean laboratory at the University of Otago.



The speciation of iron was measured using competitive ligand exchange cathodic stripping

voltammetry (CLE CSV) on samples from 40 m depth from stations both inside and outside the

patch. This technique determines the total concentration of iron binding ligands present

in the sample and their relative binding strengths. From the data generated an estimation

of the inorganic iron concentration, Fe`, can also be made, this value can be used to

approximate the amount of iron that may be available for uptake by the phytoplankton.

See SOIREE Preliminary Voyage Report

BCO-DMO Processing Notes

Generated from original file Vertical Fe.xls, Tabs: Notes and Vertical Fe
provided on the Deep-Sea Research II 48 (2001) accompanying CD-Rom

Comments preserved from the original file:

1. Dissolved (DFe) and total iron (TFe) vertical data (nM)

2. Sampling and analyses based on the methods of Bruland et al.

(1979) and Danielsson et al. (1982). For full details, see Bowie et al. (2001)

3. Decimal time is given as days in February 1999 (GMT), with 1 February 1999 0:00 = 1.0000

4. T1136: FI-CL method

5. T1143: FI-CL method



Sample analysis: Russell D. Frew (University of Otago)

Data processing and interpretation: Andrew R. Bowie (University of Plymouth and Plymouth Marine Laboratory)

BCO-DMO Edits

- parameter names modified to conform to BCO-DMO convention

- date reformatted to YYYYMMDD

- negative depths made positive for consistency with other SOIREE data

- Custom parameters generated for In/Out GFAAS Mean/StdDev
from multiple header lines

- date_UTC, time_UTC, lat, lon added from SOIREE_Stations_GoFlosSampling.xls

- 2 original column header records re-organized into one header line

- "nd" inserted in blank cells

Coverage: Southern Ocean

Project in the Southern Ocean aimed at maintaining a coherent patch of iron-enriched seawater for the duration of project and to interpret any iron-mediated effects on the patch by conducting measurements and performing experiments during this period of the project.

The Southern Ocean Iron RElease Experiment (SOIREE), was the first in situ iron fertilization experiment performed in the polar waters of the Southern Ocean. SOIREE was an interdisciplinary study involving participants from six countries, and took place in February 1999 south of the Polar Front in the Australasian-Pacific sector of the Southern Ocean.

Approximately 3800 kg of acidified FeSO4.7H2O and 165 g of the tracer sulphur hexafluoride (SF6) were added to a 65-m deep surface mixed layer over an area of ~50 km2. Initially, mean dissolved iron concentrations were ~2.7 nM, but decreased to ambient levels within days, requiring subsequent additions of 1550-1750 kg of acidified FeSO4.7H2O on days 3, 5 and 7 of the experiment.

During the 13-day site occupation, there were iron-mediated increases in phytoplankton growth rates, with marked increases in chlorophyll a (up to 2 µgl-1) and production rates (up to 1.3 gCm-2d-1). These resulted in subsequent changes in the pelagic ecosystem structure, and in the cycling of carbon, silica and sulphur, such as a 10% drawdown of surface CO2.

The SOIREE bloom persisted for >40 days following our departure from the site, as observed via SeaWiFS remotely sensed observations of Ocean Colour.

BCO-DMO Note:
All original data and metadata provided on a CD-Rom accompanying the Deep-Sea Research II 48 (2001) volume. The CD-Rom contains the main SOIREE datasets and ancillary information including the pre-experiment 'desktop' database study for site-selection, and satellite images of the SOIREE bloom.
© 2001 Elsevier Science Ltd. All rights reserved.

Related files

SOIREE Preliminary Voyage Report
SOIREE Introduction and Summary, Deep-Sea Research II 48 (2001) 2425-2438
SOIREE Cruise Track

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).