Table of Contents

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

SOIREE Surface Fe Data

Comments preserved from the original file:
SOIREE Surface Fe underway data

Author: Andrew R. Bowie (University of Plymouth and Plymouth Marine Laboratory)
Dept. of Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
Tel. +44 1752 233128, Fax +44 1752 233035, E-mail abowie@plymouth.ac.uk

SOIREE Fe data used in the preparation of the manuscript:
Bowie et al. (2001), The Fate of Added Iron during a Mesoscale Fertilisation Experiment in the Southern Ocean

This data was prepared by Andrew Bowie, whom the ownership rests with.
The data is for use for SOIREE participants only for research purposes.
Before using this data in any presentation or printed publication, please
contact the author and include full acknowledgements. All enquiries regarding
the sampling, analysis and data preparation can be directed to the address above.

Notes
1. Dissolved iron (DFe) underway data (nM).
2. All surface Fe analyses were performed using a flow injection - chemiluminescence (FI-CL) technique based on the luminol reaction using dissolved oxygen as the oxidant (Bowie et al., 1998).
3. All underway samples taken torpedo fish towed at 0.5-1 m below the surface.
4. The detection limit of the FI-CL method was 0.04 nM.
5. The analytical blank varied between 0.09 and 0.24 nM over 13 d with a mean standard deviation of 0.013 nM.
6. Contamination (suspected to be from the ship itself) resulted in a practical limit of detection for the underway mapping of 0.10-0.20 nM, which was monitored daily.
7. Out-of-patch locations determined by absence of SF6 signal. Nevertheless, continuous tracking between high Fe within patch and almost two orders lower Fe out of patch may lead to memory effect contamination of the low values for out of patch. Therefore rejections of 61 suspect out of patch "contaminated" samples
8. A '<' symbol indicates that the concentration was below the practical limit of detection.
9. The timing of samples collected from the underway system were adjusted for lag time delays due to surface water pumping and analysis (4.0-6.5 min).
10. Decimal time is given as days in February 1999 (GMT), with 1 February 1999 0:00 = 1.0000.
11. Latitudes and longitudes are taken from the DAS on RV Tangaroa (no Lagrangian correction).
12. Each worksheet corresponds to one mapping session.

References:
Bowie, A.R., Achterberg, E.P., Mantoura, R.F.C., Worsfold, P.J., 1998.
Determination of sub-nanomolar levels of iron in seawater using flow injection
with chemiluminescence detection. Analytica Chimica Acta 361, 189-200.

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.

Note
Values in brackets ('[ ]') were suspected to be contaminated

Data from original Pre-release Site Survey Notes columns below

			
date		time	Notes
19990208	0021	Ship moving slowly
19990208	0202	nd
19990208	0330	nd
19990208	0414	nd
19990208	0500	Ship moving slowly
19990208	0530	nd
19990208	0907	nd
19990208	0955	nd
19990208	1000	nd
19990209	1235	Below LOD
19990209	1243	Below LOD
19990209	1308	nd			
			
Mean		0.08		
Std. Dev.	0.03		
n		10		
2 		rejections		

See SOIREE Preliminary Voyage Report

Underway Fe Mapping
(Andrew R. Bowie, UoP / PML, UK)

Objectives
(i)To map the ambient concentration and investigate surface water changes in Fe2+,
dissolved (diss-Fe, <0.2mm) and total dissolvable (TD-Fe) iron during the experiment

(ii)To study the vertical distribution of Fe INside and OUTside the fertilised 16
patch via laboratory based analysis of sub-samples taken from daily Go-Flo casts

(iii)To perform an intercalibration exercise between FI-CL (AB) and solvent extraction
GFAAS (RF) technologies from identical samples taken from Go-Flo casts

(iv)To study the surface water distribution of Fe and other trace metals along a latitudinal
transect of the west coast of New Zealand

Analytical and Sampling Methodologies
Shipboard determinations were performed using a semi-automated flow injection chemiluminescence
(FI-CL) analyser. The technique enabled real-time analysis of Fe2+, diss-Fe and TD-Fe fractions
at the sub-nanomolar concentration level. The system is based on the oxidation of luminol, which
is catalysed by Fe2+ ions, emitting blue light. A reduction step was performed to determine the
Fe(II+III) fraction and in-line matrix elimination / sample preconcentration was achieved using
a 8-hydroxyquinoline micro-column. Surface samples were taken from a torpedo-style fish deployed
at 1-2 m and pumped directly into container designed for trace metal work. Vertical profiling
samples were collected from 5L and 30L trace metal Go-Flo sampling bottles deployed on Kevlar rope.

Preliminary Results
The FI-CL system performed with only minor problems throughout the one-month cruise period.
A minimum of 50 samples were analysed during each mapping period for Fe2+, diss-Fe and / or
TD-Fe fractions. Ambient surface water diss-Fe levels (0.08 nM) were raised to ca. 2 nM on
the first infusion, to 1 nM during infusions 2 and 3 and to 2nM on infusion 4. Rapid loss of
diss-Fe INside the patch to near ambient levels was noted after the first 3 infusions; this
was due to the conversion of the added iron sulphate heptahydrate to colloidal and particulate
phases. However, >1 nM diss-Fe persisted INside the patch for the 5 days following the 4th
infusion. Furthermore, significant concentrations of Fe2+ species existed INside the patch on
days 12 and 13 of the experiment. Maximum surface water TD-Fe levels (>5 nM) were measured on
day 8, following the 4th infusion.
 

See SOIREE Preliminary Voyage Report

Underway Fe Mapping
(Andrew R. Bowie, UoP / PML, UK)

Objectives
(i)To map the ambient concentration and investigate surface water changes in Fe2+,
dissolved (diss-Fe, <0.2mm) and total dissolvable (TD-Fe) iron during the experiment

(ii)To study the vertical distribution of Fe INside and OUTside the fertilised 16
patch via laboratory based analysis of sub-samples taken from daily Go-Flo casts

(iii)To perform an intercalibration exercise between FI-CL (AB) and solvent extraction
GFAAS (RF) technologies from identical samples taken from Go-Flo casts

(iv)To study the surface water distribution of Fe and other trace metals along a latitudinal
transect of the west coast of New Zealand

Analytical and Sampling Methodologies
Shipboard determinations were performed using a semi-automated flow injection chemiluminescence
(FI-CL) analyser. The technique enabled real-time analysis of Fe2+, diss-Fe and TD-Fe fractions
at the sub-nanomolar concentration level. The system is based on the oxidation of luminol, which
is catalysed by Fe2+ ions, emitting blue light. A reduction step was performed to determine the
Fe(II+III) fraction and in-line matrix elimination / sample preconcentration was achieved using
a 8-hydroxyquinoline micro-column. Surface samples were taken from a torpedo-style fish deployed
at 1-2 m and pumped directly into container designed for trace metal work. Vertical profiling
samples were collected from 5L and 30L trace metal Go-Flo sampling bottles deployed on Kevlar rope.

Preliminary Results
The FI-CL system performed with only minor problems throughout the one-month cruise period.
A minimum of 50 samples were analysed during each mapping period for Fe2+, diss-Fe and / or
TD-Fe fractions. Ambient surface water diss-Fe levels (0.08 nM) were raised to ca. 2 nM on
the first infusion, to 1 nM during infusions 2 and 3 and to 2nM on infusion 4. Rapid loss of
diss-Fe INside the patch to near ambient levels was noted after the first 3 infusions; this
was due to the conversion of the added iron sulphate heptahydrate to colloidal and particulate
phases. However, >1 nM diss-Fe persisted INside the patch for the 5 days following the 4th
infusion. Furthermore, significant concentrations of Fe2+ species existed INside the patch on
days 12 and 13 of the experiment. Maximum surface water TD-Fe levels (>5 nM) were measured on
day 8, following the 4th infusion.

BCO-DMO Processing Notes
Generated from original file SurfaceFe.xls, Tabs: Notes, Pre_release, and map1-map13
provided on the Deep-Sea Research II 48 (2001) accompanying CD-Rom

BCO-DMO Edits
- parameter names modified to conform to BCO-DMO convention
- individual SOIREE Map, Yr, SDAY, etc record commented and added as columns to each data record
- added negative sign to latitude values
- 2 original column header records re-organized into one header line
- No data or Bad data flag changed to BCO-DMO standard of "nd"
 

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

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).