Table of Contents

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

SEEDS 2001 Sinking Particles
mass flux (average of 4 cups) for each depth and each deployment.
POC and PON (used to calculate C and N flux).
Metals (by ICP-AES)
- Al, Ca, Fe, Mg, Mn, P, Sr, Ti, and Zn on dry material
- Ba, Cr, Cu also measured but subject to analytical problems.
- Na, K, S used to check seasalt mass balance.
Si also measured (but on different filter to metals).
d13C

Traps were suspended from each of the buoys:
- CENTRE: 20 m
- IN: 40, 60, 100, 200 m
- OUT: 20, 40, 60 and 100 m

Traps were recovered several times.

Deployment times (days):
- CENTRE: 3.95, 2.83, 2.02, 1.98, 1.93, 2.05
- IN: 3.99, 2.84, 2.03, 2.00, 1.95, 2.01
- OUT: 5.17, 3.97, 3.42

Notes from original xls file: Sinking_particles.xls
Drifting sediment trap experiment by CREST/NIES

(dm) 105 lines of comments before data begins.
(dm) all comments except 7 lines prefaced with (dm) are copied from original file.
Comments (dm) by fcsv file compiler

(dm) NOTE that I traps 200m data collected with different style (Aono type trap)

Cylindrical sediment trap of Knauer design was used.
Eight traps deployed on each cross-frame.
The cylindrical trap is separable into upper cylinder and bottom cup.
The upper cylinder has a baffle at the open end. (see picture)
(DMO Note: No picture enclosed)

- All the traps was filled with a high density gradient solution(approximately 39 permil containing 2 % formalin).
- The solution was prepared with filtered seawater sampled nearbystation of the Fe infusion and NaCl was added.
- At the deployment of the trap half volume of the high density solution might be replaced with surrounding seawater.
- Center drifter was deployed to locate the center of Fe patch which had 20 m depth trap positioning buoys radar reflector and drogue.
- Inside drifter was deployed at the distance of 0.3 mile from the center drifter which had 40 60 100 and 200 m depth traps positioning buoys and radar reflector.
- Outside drifter was deployed at the distance of 20 mile from the center drifter which had 20 40 60 and 100 m depth traps positioning buoys and radar reflector.
- Trap design of 200 m depth was different (0.16 m in diameter and 4 traps on a frame).
- The detail of the design is described in Th234 data set file.

20 m trap sample of center drifter in Run 2 was lost by an accidental event at deck recovery.
20 m trap of center drifter in Run 4 was lost because of the breakage of hydro wire.

Recovered sample in the bottom cup was transferred into 500 mL polystyrene bottle.
Formalin was added at final concentration of 5 % for preservation until on shore analysis.
The folmalin used was neutralized with sodium borate (Borax).
Large zooplankton (swimmer was removed under microscope.

Regular design traps (Knauer Type)

- 2-3: Nuclepore for biogenic Si analysis
- 4: Nuclepore for metallic element analysis
- 5: Nuclepore for spare
- 6: GF/F for C N analysis by Carlo Erba elemental analyzer (EA1110)
- 7: GF/F for C13 analysis of organic carbon by Delta Plus (Finnigan MAT combined with the Carlo Erba elemental analyzer)
- 8: GF/F for spare

Size of the filters were 47mm in diameter and pore size of Nuclepore filter was 0.6 micro meter.
Pre-weighted filter was used for filtration.
The pre-weighting procedure was identical to the sample weighting.
Filter with trapped material was immediately frozen in -30 degree C freezer.
Filters were dried in a vacuum freeze dryer.
After drying the filter it was kept in a clean balance room controlled at 23 degree C and 50 % humidity.
The reproducibility of the weight measurement was 0.05 mg for each filter.
Total mass flux was calculated from 4 replicate measurement of Nuclepore filters.
The weight of GF/F samples were also measured however the stability of the weight
was poorer than that of Nuclepore filter.
For C/N analysis GF/F filter was fumed in a desiccator containing conc.
HCl to vaporize the inorganic carbon.

Trap dimensions:
- Length (L) m 0.63
- Inside diameter (Di) m 0.07
- Outside diameter (Do) m 0.075
- Aspect ratio (AR) 8.86
- Collection area (A) m2 0.00385
- Trap volume (V) m3 0.00239
- Trap volume (V) litres 2.386
- Baffle length (Lb) m 0.076
- Baffle diameter (Dib) m 0.013
- Baffle aspect ratio (ARb) 5.85

Aono type trap (used I traps at 200 m only collection area 0.020106 m2
Trap collection area 0.003848 m2

Notes from original xls file: Sinking_particles.xls
Total mass flux measurement
Nuclepore filter weight with sample was measured for 4 cups from
one depth of the drifting sediment trap.

CN analysis
No. 6 GF/F filter was used for CN analysis. of (DMO Note: ????)
The filters were freeze-dried and then inorganic carbon was removed by an acid treatment in (DMO Note: ????)
The filters were freeze-dried and then fumed in desiccator with conc. HCl for 4-5 hours to remove inorganic carbon.
Organic carbon and nitrogen were analyzed by EA1110 elemental analyzer (Carlo Erba) calibrated with acetoanilide (C8H9NO) standard reagent.
C and N fluxes were calculated from mg yield of C and N with collection area of the trap and drifting period.

ICPAES analysis of trapped material of drifting sediment trap acid digestion by HNO3/HClO4/HF ppm (mg/kg in dry wt.
Nuclepore filter with sample was enclosed in a double sealed Teflon digestion vessel with stainless steel outer jacket with 2 ml HNO3 and 1ml HClO4.
The digestion vessel was heated at 150 degree C for 7 hours to decompose organic material.
One ml of HF was added into the Teflon vessel and silicate was decomposed on a hot plate.
The final weight of sample solution was adjusted to 4 g and served to ICP atomic emission spectrometric analysis.
Blank was corrected from with the results of the same procedure only using blank Nuclepore filter and acid reagents.
Nippon Jarrel Ash type ICAP750 was used for the ICPAES analysis.

Biogenic Si was measured using different Nuclepore filter with that for metallic element analysis.
Nuclepore filter with trapped material was treated with 0.5 M Na2CO3 solution for 3 hours at 85 degree C.
The extracted biogenic Si was measured by ICPAES same as metallic elements.
Samples for 200 m depth (from Aono type trap had different history from other depths.
Samples other than 200 m preserved under neutralized pH formalin solution and applied swimmer picking out procedure were filtered within two months after recovery.
Because 200 m trap has two sample cups samples were divided after five months of recovery and served for ICP analysis for Si and other elements.
C/N analysis fo samples for 200 m depth was done in similar period with other depths.
The total mass of 200 m analysis suming up for C N Si and elements are significantly smaller than 100 %.
These results are not accurate than other depths.
Filter weight is that of the digested filter different from the average of four Nuclepore filter.

Al Ca Fe Mg Mn P Sr Ti Zn This element group was well within ICPAES measurement range with minimum blank correction.
The element group (Ba Cr Cu and Na K Shas analytical problem relating to blank correction and digestion efficiency
B comes from preservative.
Na K and S are nominated to check analytical accuracy to sum up the total mass which usually comes from seawater components.

Elemental flux was calculated from concentration of the element multiplied by the total mass flux estimated from the trapped material weight on the four Nuclepore filter.
Calculated sum of all the elements well agree with 100 %.
Silicate Ca was estimated using crustal abundance of Ca to Al and the rest of Ca was estimated as carbonate.
Inorganic carbon was estimated from the carbonate calcium.
The total sum of elements other than 200 m samples are excellent.
Preservation for 200 m samples might not be good.
(dm) mass check calculations assume element in stated form.
(dm) calculatedMass = flux / atomic mass element * molecular mass stated form

Isotope analysis of organic carbon of trapped material
No. 7 GF/F filter for each trap was served for carbon isotopic analysis by
Carlo Erba elemental analyzer (EA1110) combined with a mass spectrometer (Delta Plus Finniga MAT).
The filter was fumed by HCl.
Filter used indicates the division of sample served for combustion furnace of the elemental analyzer.
MCC is Mass Check Calculation (added to params toward end of records

BCO-DMO Processing Notes
CSV file generated by Doug Mackie from original spreadsheet Sinking_particles.xls

BCO-DMO Edits
- Parameter names modified to conform to BCO-DMO convention
- lat/lon for deployment and recovery added from buoy drift data

An in situ test of the iron limitation hypothesis in the subarctic North Pacific Oceanwas performed. First experiment of two (see SEEDS 2004)

A single enrichment of dissolved iron caused a large increase in phytoplanktonstanding stock and decreases in macronutrients and dissolved carbon dioxide. The dominant phytoplankton species shifted after the iron addition from pennate diatoms to a centric diatom, Chaetoceros debilis, that showed a very high growth rate, 2.6 doublings per day. Conclusion was that the bioavailability of iron regulates the magnitude of the phytoplankton biomass and the key phytoplankton species that determine the biogeochemical sensitivity to iron supply of high-nitrate, low-chlorophyll waters.

Data was collected at a total of 13 stations and from 3 moored sediment traps.
- Stations were occupied IN patch for days 0, 2, 4, 7, 9, 11 and 13.
- Stations were occupied OUT patch for days 2, 4, 7, 9, 11, 13.

It is not explicitly stated but it appears that at all stations two CTDsampling rosette casts were made: clean and rms. The clean rosette appears to have typically sampled the mixed layer (<50 m) e.g. 5, 10, 20, 30, 50 m. The rms rosette appears to have typically sampled the euphotic zone (<200m) e.g. 10, 20, 30, 40, 50, 80, 100, 150, 200 m.

Sediment traps were deployed at:
- CENTRE: 20 m
- IN: 40, 60, 100, 200 m
- OUT: 20, 40, 60 and 100 m

Traps were recovered several times. Deployment times (days):
- CENTRE: 3.95, 2.83, 2.02, 1.98, 1.93, 2.05
- IN: 3.99, 2.84, 2.03, 2.00, 1.95, 2.01
- OUT: 5.17, 3.97, 3.42

BCO-DMO/Doug Mackie Note:
Throughout these data, stations are identified as D2-I, D2-O, etc.
D2-I indicates "Day 2, in patch station".
while D2-O indicates "Day 2, out patch station".
This applies to all station identifiers.

Related file

SEEDS 2001 Project Documentation

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).