http://lod.bco-dmo.org/id/dataset/969502
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2025-07-22
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Concentrations of iron bound to humic-like substances and total iron-binding capacity of humic-like substances from discrete samples collected on the GP17-ANT RVIB Palmer cruise NBP24-01 in the Amundsen Sea from Nov 2023 to Jan 2024
2025-07-22
publication
2025-07-22
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2025-07-29
publication
https://doi.org/10.26008/1912/bco-dmo.969502.1
Laura Ellen Moore
Oregon State University
principalInvestigator
Kristen Nicolle Buck
Oregon State University
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Moore, L., Buck, K. N. (2025) Concentrations of iron bound to humic-like substances and total iron-binding capacity of humic-like substances from discrete samples collected on the GP17-ANT RVIB Palmer cruise NBP24-01 in the Amundsen Sea from Nov 2023 to Jan 2024. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2025-07-22 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.969502.1 [access date]
GP17-ANT Fe-binding humic-like substances Dataset Description: Methods and Sampling: <p><strong>Water column sampling:</strong><br />
The full water column of 27 stations in the Amundsen Sea was sampled between 8 December 2023 and 13 January 2024 aboard the R/V IB Nathaniel B. Palmer. Depth profile samples were collected from the GEOTRACES trace metal clean rosette sampling system (GTC CTD) outfitted with 24 modified 12-liter (L) GO-FLO (General Oceanics) sampling bottles (Cutter and Bruland, 2012). Surface water (~2 meters) samples for the depth profiles were collected using a trace metal clean surface pump "towfish" system (FISH).</p>
<p>From the trace metal clean rosette and towfish, samples for humic-like substances were filtered (0.2 micrometer (µm), Acropak) inline and collected inside a trace metal clean sampling van. Samples were collected in acid-cleaned, Milli-Q-conditioned, and triple-rinsed narrow-mouth fluorinated high-density polyethylene bottles (FPE; Nalgene) and analyzed shipboard for dissolved iron speciation by Dr. Léo Mahieu in Dr. Kristen Buck's lab before freezing at -20 degrees Celsius (ºC) for shore-based humic-like substance analyses at Oregon State University.</p>
<p><strong>Sample analyses – humic-like substances:</strong><br />
Humic-like substances were measured using cathodic stripping voltammetry following the method first developed by Laglera et al. (2007) and updated by Sukekava et al. (2018). All samples were analyzed using a polarographic 797 VA Computrace (Metrohm) stand equipped with a hanging mercury drop electrode, platinum rod auxiliary electrode, Ag/AgCl reference electrode, and an acid-cleaned Teflon analytical cell. Briefly, frozen samples were set out to thaw overnight at room temperature in the dark. The following day, 10 milliliter (mL) sub-samples were aliquoted into each of 2 paired acid-cleaned, pre-conditioned 50 mL polypropylene vials. The pH of the samples was then set to 8.2 with the addition of 50 microliters (μL) of 1.5 molar (M) boric acid buffer. Iron standard was added to one of the paired vials (vial B, final concentration 60 nanomolar (nM)) to saturate all the humic-like substance binding groups in the solution. Both aliquots were then left to equilibrate for a minimum of 14 hours. After the equilibration period, 500 μL of the 0.4M KBrO<sub>3</sub><sup>- </sup>catalyst was dispensed into the cell with each aliquot immediately prior to analysis. Electrochemical analysis was performed using linear sweep voltammetry (-0.1 to -1 volts (V), scan rate 50 millivolts per second (mV s-1)) with a 120-second deposition period with stirring at -0.1V. Measurements were run in triplicate with a 300-second purge step with high-purity N<sub>2</sub> gas prior to analyzing each aliquot. For each sample, the Fe-free aliquot (vial A) was analyzed first, immediately followed by the Fe-saturated aliquot (vial B). Three standard additions of Fe-saturated SRFA standard (0.1, 0.2, and 0.3 milligrams (mg) SRFA per liter) were then added successively to the Fe-saturated aliquot to generate a calibration curve. A 70s N<sub>2</sub> purge was included after each addition to ensure oxygen removal and all additions were measured in triplicate. The Teflon analytical cell was rinsed thoroughly with Milli-Q water between samples to minimize carryover.</p>
<p>Peak heights were extracted from scans using ECDSOFT, then converted into the concentration of electroactive humic substances (micrograms (μg) eq SRFA<sup>-1</sup>) using the slope of the curve generated by the three standard additions. The standard addition slope was applied to the peaks obtained for both vials A and B to obtain the ambient Fe-binding humic and total Fe-binding humic concentrations, respectively, in mg SRFA eq per liter. Units were then adjusted to nM Fe eq using the measured binding capacity of SRFA in seawater 14.6 ± 0.4 nM Fe mg SRFA<sup>-1</sup>. Variability between triplicate scans averaged 0.02 nM Fe eq for both ambient and total humic results and variability between replicate samples averaged 0.05 (median 0.03) nM Fe eq and 0.06 (median 0.04) nM Fe eq for ambient and total humic-like substances, respectively. The limit of detection (LOD) was calculated as three times the standard deviation of triplicate scans in the lowest measured ambient Fe-binding humic concentration (0.06 ± 0.02 nM Fe eq) and was estimated to be 0.05 nM Fe eq. All measured values were above the LOD.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2300915 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2300915
Funding provided by NSF Office of Polar Programs (formerly NSF PLR) (NSF OPP) Award Number: OPP-2317664 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2317664
completed
Laura Ellen Moore
Oregon State University
moorel6@oregonstate.edu
pointOfContact
Kristen Nicolle Buck
Oregon State University
541-737-7401
2651 SW Orchard Avenue CEOAS
Corvallis
OR
97331
USA
kristen.buck@oregonstate.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
CRUISE_ID
SECT_ID
STNNBR
PLATFORM
CASTNO
SAMPNO
EVENT_NO
GEOTRC_SAMPNO
BTLNBR
DATE
TIME
ISO_DateTime_UTC
LATITUDE
LONGITUDE
DEPTH
CTDPRS
SAMPDEPTH
BTL_DATE
BTL_TIME
BTL_ISO_DateTime_UTC
BTL_LAT
BTL_LON
HSFe_D_CONC
HSFe_D_STDEV
HSFe_D_COUNT
HSFe_D_FLAG
THSFe_D_CONC
THSFe_D_STDEV
THSFe_D_COUNT
THSFe_D_FLAG
GEOTRACES trace metal clean rosette sampling system (GTC CTD)
Towfish
General Oceanics 12-L GO-FLO bottle
Metrohm VA 797
theme
None, User defined
Cruise identfier
station
instrument
cast
sample identification
event
bottle
date
time of day
ISO_DateTime_UTC
latitude
longitude
depth_bottom
water pressure
depth
Iron
number
quality flag
featureType
BCO-DMO Standard Parameters
CTD Sea-Bird SBE 911plus
GeoFish Towed near-Surface Sampler
GO-FLO Bottle
Metrohm 797 VA Computrace voltammetry system
instrument
BCO-DMO Standard Instruments
NBP2401
service
Deployment Activity
Punta Arenas, Chile to Lyttelton, New Zealand
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
U.S. GEOTRACES
http://www.geotraces.org/
U.S. GEOTRACES
GEOTRACES is a SCOR sponsored program; and funding for program infrastructure development is provided by the U.S. National Science Foundation.
GEOTRACES gained momentum following a special symposium, S02: Biogeochemical cycling of trace elements and isotopes in the ocean and applications to constrain contemporary marine processes (GEOSECS II), at a 2003 Goldschmidt meeting convened in Japan. The GEOSECS II acronym referred to the Geochemical Ocean Section Studies To determine full water column distributions of selected trace elements and isotopes, including their concentration, chemical speciation, and physical form, along a sufficient number of sections in each ocean basin to establish the principal relationships between these distributions and with more traditional hydrographic parameters;
* To evaluate the sources, sinks, and internal cycling of these species and thereby characterize more completely the physical, chemical and biological processes regulating their distributions, and the sensitivity of these processes to global change; and
* To understand the processes that control the concentrations of geochemical species used for proxies of the past environment, both in the water column and in the substrates that reflect the water column.
GEOTRACES will be global in scope, consisting of ocean sections complemented by regional process studies. Sections and process studies will combine fieldwork, laboratory experiments and modelling. Beyond realizing the scientific objectives identified above, a natural outcome of this work will be to build a community of marine scientists who understand the processes regulating trace element cycles sufficiently well to exploit this knowledge reliably in future interdisciplinary studies.
Expand "Projects" below for information about and data resulting from individual US GEOTRACES research projects.
U.S. GEOTRACES
largerWorkCitation
program
Collaborative Research: U.S. GEOTRACES GP17-OCE and GP17-ANT: Characterizing iron-binding organic ligands in the Southern Ocean and implications for iron cycling in the global ocean
https://osprey.bco-dmo.org/project/898058
Collaborative Research: U.S. GEOTRACES GP17-OCE and GP17-ANT: Characterizing iron-binding organic ligands in the Southern Ocean and implications for iron cycling in the global ocean
<p><strong>NSF Award Abstract</strong><br />
Iron is an essential element for life and plays an important role in defining how much atmospheric carbon dioxide is taken up into the ocean by phytoplankton. However, iron cycling is closely governed by the chemistry of seawater; nearly all iron in seawater is associated with various unknown organic compounds, called iron-binding ligands, which impact whether and how iron is utilized by organisms and the distribution of iron throughout the ocean. Detail understanding of the cycling of organic iron-binding ligands is necessary to understand iron cycling in the oceans and the connections between iron cycling and atmospheric carbon. The proposed research will be carried out as a part of US GEOTRACES expedition to test the hypothesis that the Southern Ocean is a globally significant source of iron-binding organic ligands, and that different sources of these organic molecules lead to different iron-ligand characteristics. The US GEOTRACES program is a large collaborative effort to sample ocean systems at high resolution for a suite of key trace elements and isotopes. The South Pacific and Southern Ocean regions targeted by the upcoming US GEOTRACES GP17 cruises are important locations of water mass formation and the subsequent transport of carbon and nutrients to the global ocean. Organic ligands produced in these regions thus have important implications for the stabilization, reactivity, and residence time of iron along the path of global water mass circulation and could impact the global oceanic inventory of dissolved iron.</p>
<p>This project will measure the distribution of iron-binding organic ligands, and identify specific organic molecules that comprise these ligands, in field and experimental samples collected on upcoming US GEOTRACES cruises in the South Pacific (GP17-OCE) and Southern Ocean (GP17-ANT). These datasets will be utilized to conduct the first extensive intercalibration of the two most widely used approaches for characterizing iron-binding organic ligands, providing important insight into these datasets and how they can be synthesized to improve understanding of iron cycling in the oceans. All data from this project will be made publicly available. Project activities will provide educational and training opportunities for middle school, high school, undergraduate, and graduate students, and results will be shared with the public through the development of virtual reality modules and via local outreach events.</p>
<p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p>
GP17-OCE and GP17-ANT organic iron-binding ligands
largerWorkCitation
project
US GEOTRACES GP17 Section: Amundsen Sea Sector of the Antarctic Continental Margin (GP17-ANT)
https://www.geotraces.org/
US GEOTRACES GP17 Section: Amundsen Sea Sector of the Antarctic Continental Margin (GP17-ANT)
<p>U.S. GEOTRACES extended its meridional transect, initiated on the 2018 GP15 Alaska-Tahiti expedition, south to the Antarctic ice edge and then east to Chile with GP17-OCE (December 2022 - January 2023). Because of the potentially important trace elements and isotopes (TEIs) inputs and transformations occurring in Antarctic waters and shelves, GP17 also had a second leg, GP17-ANT (November 29, 2023 - January 30, 2024) into coastal and shelf waters of Antarctica’s Amundsen Sea. Further information is available on the <a href="https://usgeotraces.ldeo.columbia.edu/content/gp17-ant" target="_blank">US GEOTRACES website</a>.</p>
<p><em>NSF Project Title:</em> Collaborative Research: Management and Implementation of US GEOTRACES GP17 Section: Amundsen Sea Sector of the Antarctic Continental Margin (GP17-ANT)</p>
<p><em>NSF Award Abstract:</em><br />
This project will support the management and implementation of a 60-day research cruise to the Amundsen Sea sector of the Antarctic continental margin to collect samples for measurements of a broad suite of trace elements and isotopes ('TEIs'), as part of the U.S. GEOTRACES program. GEOTRACES is a global effort in the field of Chemical Oceanography, the goal of which is to understand the distributions of trace elements and their isotopes in the ocean. Determining the distributions of these elements and isotopes will increase the understanding of processes that shape their distributions and also the processes that depend on these elements. Key TEIs include essential micronutrients such as iron and zinc; 'tracers' such as aluminum, manganese, and isotopes of nitrogen, thorium and neodymium that can be used to investigate modern and ancient ocean processes; and elements such as lead that are indicative of human activities. In the Southern Ocean, the Antarctic continental margins are important as sources of micronutrient trace elements such as iron, which is required to support biological production and carbon export over the Antarctic shelf and in offshore waters of the Antarctic Circumpolar Current. Moreover, these regions are experiencing rapid environmental changes that are expected to impact oceanic circulation and biogeochemical cycles, for which TEIs provide crucial data needed to test and refine numerical models of the Earth system. The Amundsen Sea sector holds particular interest because of the pronounced, decadal-scale increases in the melting rates of glacial ice shelves that border the region, driven by intrusions of warm Circumpolar Deep Water onto the continental shelf. This melting has potentially major impacts on global sea level, on the formation of Antarctic Bottom Water in the Ross Sea, and on the regional ecosystem.</p>
<p>The cruise will comprise essential sampling operations (collection and shipboard processing) and ancillary measurements (hydrography, nutrients, algal pigments) in support of multiple, individual science projects, following the successful model of previous U.S. GEOTRACES cruises in the Atlantic, Pacific and Arctic ocean basins. The cruise will sample the ocean region between 100°W and 135°W, with stations ranging from 67°S in the Antarctic Circumpolar Current southward to the Amundsen Sea continental shelf, including stations adjacent to several rapidly melting ice shelves and in highly-productive shelf polynyas. Water column samples will be collected using conventional and trace-metal clean CTD-rosette systems, in-situ high-volume pumps, and a towed fish sampler or small boat, using established methods. Sampling time will also be provided for collection of sea ice, floating glacial ice, and seafloor sediments. To facilitate coordination with a complementary open-ocean cruise and ensure access to the study region to document the impact of biological processes, the cruise is planned for late austral summer (late January-late March). Beyond the disciplinary contributions, the proposed research will contribute knowledge concerning the cryosphere and its impacts on global sea level and ocean circulation, regional ecosystems and biological processes, ocean-atmosphere interactions, and past and future environmental change. The project will contribute to STEM education and outreach through the participation of an NSF-funded PolarTREC education professional, and a K-12 STEM program for students from underserved and underrepresented schools run by Rutgers University education specialists. To foster public engagement, the investigators will partner with the UCSC Science Communication Program to engage freelance science journalists to profile research in this spectacular and harsh Antarctic environment.</p>
GP17-ANT
largerWorkCitation
project
Postdoctoral Fellowship: OPP-PRF: Understanding the Role of Specific Iron-binding Organic Ligands in Governing Iron Biogeochemistry in the Southern Ocean
https://osprey.bco-dmo.org/project/948047
Postdoctoral Fellowship: OPP-PRF: Understanding the Role of Specific Iron-binding Organic Ligands in Governing Iron Biogeochemistry in the Southern Ocean
<p><em>NSF Award Abstract:</em><br />
Iron is an essential nutrient in the global ocean, required by phytoplankton to perform several essential cellular functions. In the Southern Ocean, iron is especially scarce and exerts a primary control on primary production and resulting CO2 uptake by the surface ocean. Most dissolved iron in the Southern Ocean is bound to a complex mixture of organic iron-binding compounds, called ligands. The concentrations and identities of these ligands control iron bioavailability, reactivity, and transport. Exopolysaccharides (EPS) are a particularly important group of ligands that are produced in high concentrations by local microbial communities for a variety of functions, including as cryoprotectants. Despite the known importance of EPS, most iron-binding ligand studies focus on total ligand concentrations or siderophore identification. Siderophores, small iron-binding molecules produced as a microbial iron acquisition strategy, are thought to play a disproportionate role in iron cycling due to their unusually high iron-binding affinities. This project adds essential EPS concentration measurements to a subset of samples from the 2023 U.S. GEOTRACES GP17-ANT expedition to the Amundsen Sea. This project integrates EPS, siderophores and bulk ligand measurements for the first time, thereby offering unprecedented insights into how the composition of organic ligands governs the supply and fate of iron to the Southern Ocean.</p>
<p>The research plan involves a combination of field and experimental approaches. Field samples for electrochemical EPS analysis will be collected on a GP17-ANT transect spanning from the ice edge to open water. Previously funded paired samples of bulk ligand concentrations and siderophore identification will also be taken along the same transect. Results from the three analyses will be combined to assess the relative contributions of EPS and siderophores to the total ligand pool and interpret their impact on iron biogeochemical cycling in the region. Lab experiments will be performed to evaluate whether EPS alters the size fractionation of siderophores and iron in seawater, shuttling both species into the particulate phase. Experimental results will then be used to interpret the integrated field data and improve understanding of the impact of ligands on iron transport and bioavailability in the Amundsen Sea.</p>
<p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p>
GP17-ANT Humics
largerWorkCitation
project
eng; USA
oceans
Punta Arenas, Chile to Lyttelton, New Zealand
-133.0225
-99.6837
-74.3892
-66.9774
2023-12-08
2024-01-13
Amundsen Sea Sector of the Antarctic Continental Margin
0
BCO-DMO catalogue of parameters from Concentrations of iron bound to humic-like substances and total iron-binding capacity of humic-like substances from discrete samples collected on the GP17-ANT RVIB Palmer cruise NBP24-01 in the Amundsen Sea from Nov 2023 to Jan 2024
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/969548.rdf
Name: CRUISE_ID
Units: unitless
Description: <p>Cruise identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/969549.rdf
Name: SECT_ID
Units: unitless
Description: <p>Name of GEOTRACES cruise section</p>
http://lod.bco-dmo.org/id/dataset-parameter/969550.rdf
Name: STNNBR
Units: unitless
Description: <p>Station number</p>
http://lod.bco-dmo.org/id/dataset-parameter/969551.rdf
Name: PLATFORM
Units: unitless
Description: <p>Sampling system used. GTC CTD = GEOTRACES trace metal CTD rosette. FISH = towfish.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969552.rdf
Name: CASTNO
Units: unitless
Description: <p>Cast number</p>
http://lod.bco-dmo.org/id/dataset-parameter/969553.rdf
Name: SAMPNO
Units: unitless
Description: <p>Order of samples taken in each cast</p>
http://lod.bco-dmo.org/id/dataset-parameter/969554.rdf
Name: EVENT_NO
Units: unitless
Description: <p>Event number</p>
http://lod.bco-dmo.org/id/dataset-parameter/969555.rdf
Name: GEOTRC_SAMPNO
Units: unitless
Description: <p>GEOTRACES sample number</p>
http://lod.bco-dmo.org/id/dataset-parameter/969556.rdf
Name: BTLNBR
Units: unitless
Description: <p>Bottle number (GOFLO # for GTC CTD) used for sample collection. Samples were collected directly inline from towfish and noted FISH.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969557.rdf
Name: DATE
Units: unitless
Description: <p>Date in ship time when sampling was initiated</p>
http://lod.bco-dmo.org/id/dataset-parameter/969558.rdf
Name: TIME
Units: unitless
Description: <p>Ship time (UTC) when field sampling platform was deployed</p>
http://lod.bco-dmo.org/id/dataset-parameter/969559.rdf
Name: ISO_DateTime_UTC
Units: unitless
Description: <p>Date and time (UTC) in ISO 8601 format when sampling was initiated</p>
http://lod.bco-dmo.org/id/dataset-parameter/969560.rdf
Name: LATITUDE
Units: decimal degrees North
Description: <p>Ship position when sampling platform was deployed</p>
http://lod.bco-dmo.org/id/dataset-parameter/969561.rdf
Name: LONGITUDE
Units: decimal degrees East
Description: <p>Ship position when sampling platform was deployed</p>
http://lod.bco-dmo.org/id/dataset-parameter/969562.rdf
Name: DEPTH
Units: meters (m)
Description: <p>Seafloor depth in meters. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969563.rdf
Name: CTDPRS
Units: decibars (db)
Description: <p>Pressure in decibar of sample collection. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969564.rdf
Name: SAMPDEPTH
Units: meters (m)
Description: <p>Depth of sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/969565.rdf
Name: BTL_DATE
Units: unitless
Description: <p>Date sample collected. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969566.rdf
Name: BTL_TIME
Units: unitless
Description: <p>Time (UTC) sample collected. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969567.rdf
Name: BTL_ISO_DateTime_UTC
Units: unitless
Description: <p>Date and time (UTC) in ISO 8601 format when bottle sample was collected. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969568.rdf
Name: BTL_LAT
Units: decimal degrees North
Description: <p>Ship position when sample was collected. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969569.rdf
Name: BTL_LON
Units: decimal degrees East
Description: <p>Ship position when sample was collected. Blank/empty for towfish samples.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969570.rdf
Name: HSFe_D_CONC
Units: nanomoles Fe equivalents per liter (NMOL_FE_EQ/L)
Description: <p>Concentration of iron bound to humic-like substances in field samples; blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969571.rdf
Name: HSFe_D_STDEV
Units: nanomoles Fe equivalents per liter (NMOL_FE_EQ/L)
Description: <p>Standard deviation replicate iron bound to humic substances concentration measurements in field samples. If no replicates, standard deviation reported is that of replicate scans of the same aliquot. Blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969572.rdf
Name: HSFe_D_COUNT
Units: unitless
Description: <p>Number of separate analyses of this sample used to compute average concentration and standard deviation. Blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969573.rdf
Name: HSFe_D_FLAG
Units: unitless
Description: <p>Quality flag for HSFe_D_CONC. Blank/empty when no sample was available for analyses. See 'Processing Description' section of metadata for flag definitions.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969574.rdf
Name: THSFe_D_CONC
Units: nanomoles Fe equivalents per liter (NMOL_FE_EQ/L)
Description: <p>Total iron binding capacity of humic substances in field samples; blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969575.rdf
Name: THSFe_D_STDEV
Units: nanomoles Fe equivalents per liter (NMOL_FE_EQ/L)
Description: <p>Standard deviation of replicate total iron binding capacity of humic substances measurements in field samples. If no replicates, standard deviation reported is that of replicate scans of the same aliquot. Blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969576.rdf
Name: THSFe_D_COUNT
Units: unitless
Description: <p>Number of separate analyses of this sample used to compute average concentration and standard deviation. Blank/empty when no sample was available for analyses.</p>
http://lod.bco-dmo.org/id/dataset-parameter/969577.rdf
Name: THSFe_D_FLAG
Units: unitless
Description: <p>Quality flag for THSFe_D_CONC. Blank/empty when no sample was available for analyses. See 'Processing Description' section of metadata for flag definitions.</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
77422
https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/f70c753e-22c4-4168-b600-d9d270958699/content
download
https://doi.org/10.26008/1912/bco-dmo.969502.1
download
onLine
dataset
<p><strong>Water column sampling:</strong><br />
The full water column of 27 stations in the Amundsen Sea was sampled between 8 December 2023 and 13 January 2024 aboard the R/V IB Nathaniel B. Palmer. Depth profile samples were collected from the GEOTRACES trace metal clean rosette sampling system (GTC CTD) outfitted with 24 modified 12-liter (L) GO-FLO (General Oceanics) sampling bottles (Cutter and Bruland, 2012). Surface water (~2 meters) samples for the depth profiles were collected using a trace metal clean surface pump "towfish" system (FISH).</p>
<p>From the trace metal clean rosette and towfish, samples for humic-like substances were filtered (0.2 micrometer (µm), Acropak) inline and collected inside a trace metal clean sampling van. Samples were collected in acid-cleaned, Milli-Q-conditioned, and triple-rinsed narrow-mouth fluorinated high-density polyethylene bottles (FPE; Nalgene) and analyzed shipboard for dissolved iron speciation by Dr. Léo Mahieu in Dr. Kristen Buck's lab before freezing at -20 degrees Celsius (ºC) for shore-based humic-like substance analyses at Oregon State University.</p>
<p><strong>Sample analyses – humic-like substances:</strong><br />
Humic-like substances were measured using cathodic stripping voltammetry following the method first developed by Laglera et al. (2007) and updated by Sukekava et al. (2018). All samples were analyzed using a polarographic 797 VA Computrace (Metrohm) stand equipped with a hanging mercury drop electrode, platinum rod auxiliary electrode, Ag/AgCl reference electrode, and an acid-cleaned Teflon analytical cell. Briefly, frozen samples were set out to thaw overnight at room temperature in the dark. The following day, 10 milliliter (mL) sub-samples were aliquoted into each of 2 paired acid-cleaned, pre-conditioned 50 mL polypropylene vials. The pH of the samples was then set to 8.2 with the addition of 50 microliters (μL) of 1.5 molar (M) boric acid buffer. Iron standard was added to one of the paired vials (vial B, final concentration 60 nanomolar (nM)) to saturate all the humic-like substance binding groups in the solution. Both aliquots were then left to equilibrate for a minimum of 14 hours. After the equilibration period, 500 μL of the 0.4M KBrO<sub>3</sub><sup>- </sup>catalyst was dispensed into the cell with each aliquot immediately prior to analysis. Electrochemical analysis was performed using linear sweep voltammetry (-0.1 to -1 volts (V), scan rate 50 millivolts per second (mV s-1)) with a 120-second deposition period with stirring at -0.1V. Measurements were run in triplicate with a 300-second purge step with high-purity N<sub>2</sub> gas prior to analyzing each aliquot. For each sample, the Fe-free aliquot (vial A) was analyzed first, immediately followed by the Fe-saturated aliquot (vial B). Three standard additions of Fe-saturated SRFA standard (0.1, 0.2, and 0.3 milligrams (mg) SRFA per liter) were then added successively to the Fe-saturated aliquot to generate a calibration curve. A 70s N<sub>2</sub> purge was included after each addition to ensure oxygen removal and all additions were measured in triplicate. The Teflon analytical cell was rinsed thoroughly with Milli-Q water between samples to minimize carryover.</p>
<p>Peak heights were extracted from scans using ECDSOFT, then converted into the concentration of electroactive humic substances (micrograms (μg) eq SRFA<sup>-1</sup>) using the slope of the curve generated by the three standard additions. The standard addition slope was applied to the peaks obtained for both vials A and B to obtain the ambient Fe-binding humic and total Fe-binding humic concentrations, respectively, in mg SRFA eq per liter. Units were then adjusted to nM Fe eq using the measured binding capacity of SRFA in seawater 14.6 ± 0.4 nM Fe mg SRFA<sup>-1</sup>. Variability between triplicate scans averaged 0.02 nM Fe eq for both ambient and total humic results and variability between replicate samples averaged 0.05 (median 0.03) nM Fe eq and 0.06 (median 0.04) nM Fe eq for ambient and total humic-like substances, respectively. The limit of detection (LOD) was calculated as three times the standard deviation of triplicate scans in the lowest measured ambient Fe-binding humic concentration (0.06 ± 0.02 nM Fe eq) and was estimated to be 0.05 nM Fe eq. All measured values were above the LOD.</p>
Specified by the Principal Investigator(s)
<p>Data were flagged using the SeaDataNet quality flag scheme recommended by GEOTRACES (<a href="https://www.geotraces.org/geotraces-quality-flag-policy/" target="_blank">https://www.geotraces.org/geotraces-quality-flag-policy/</a>) and described below. Notes specific to the application of these flags to this dataset are noted in brackets […].</p>
<p><strong>0</strong>: No Quality Control: No quality control procedures have been applied to the data value. This is the initial status for all data values entering the working archive. [Not used].</p>
<p><strong>1</strong>: Good Value: Good quality data value that is not part of any identified malfunction and has been verified as consistent with real phenomena during the quality control process. [Used for analyses that included replicates].</p>
<p><strong>2</strong>: Probably Good Value: Data value that is probably consistent with real phenomena, but this is unconfirmed or data value forming part of a malfunction that is considered too small to affect the overall quality of the data object of which it is a part. [Used when no replicates were available to further verify the quality of the data].</p>
<p><strong>3</strong>: Probably Bad Value: Data value recognized as unusual during quality control that forms part of a feature that is probably inconsistent with real phenomena. [Used for Fe bound to humics data when concentration of Fe bound to humics is greater than preliminary Fe concentrations by more than 0.03 nM (which is the median std dev of replicate analyses), or where no preliminary Fe data is available, but interpolated Fe values are greater than Fe-humic].</p>
<p><strong>4</strong>: Bad Value: An obviously erroneous data value. [Used when anomalously high or low values of Fe-bound to humics or total Fe-binding capacity of humics is found in a depth profile with no correlation to existing physical or chemical data].</p>
<p><strong>5</strong>: Changed Value: Data value adjusted during quality control. Best practice strongly recommends that the value before the change be preserved in the data or its accompanying metadata. [Not used].</p>
<p><strong>6:</strong> Value Below Detection Limit: The level of the measured phenomenon was less than the limit of detection (LOD) for the method employed to measure it. [Not used].</p>
<p><strong>7</strong>: Value in Excess: The level of the measured phenomenon was too large to be quantified by the technique employed to measure it. The accompanying value is the measurement limit for the technique. [Not used].</p>
<p><strong>8</strong>: Interpolated Value: This value has been derived by interpolation from other values in the data object. [Not used].</p>
<p><strong>9</strong>: Missing Value: The data value is missing. Any accompanying value will be a magic number representing absent data [When sample was not collected the notation 'na' for 'not applicable' was used].</p>
<p><strong>A</strong>: Value Phenomenon Uncertain: There is uncertainty in the description of the measured phenomenon associated with the value such as chemical species or biological entity. [Not used]</p>
Specified by the Principal Investigator(s)
- Imported original file "BCO_DMO_Moore_GP17ANT_HS-FeL.xlsx" into the BCO-DMO system.
- Marked "NA" as a missing data value (missing data are blank/empty in the final CSV file).
- Created date-time fields in ISO 8601 format.
- Saved the final file as "969502_v1_gp17-ant_hs-fel.csv".
Specified by BCO-DMO Data Managers
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
GEOTRACES trace metal clean rosette sampling system (GTC CTD)
GEOTRACES trace metal clean rosette sampling system (GTC CTD)
PI Supplied Instrument Name: GEOTRACES trace metal clean rosette sampling system (GTC CTD) PI Supplied Instrument Description:The U.S. GEOTRACES trace element carousel sampling system (GTC rosette) was comprised of an SBE-9/11plus CTD/deck unit, and 24 x 12-liter Go-Flo bottles (plus spares). The GTC system sensor array consisted of dual SeaBird SBE-3 temperature and SBE-4C conductivity sensors, an SBE-43 dissolved oxygen sensor, a Seapoint fluorometer, and a WetLabs C-Star transmissometer. The GTC rosette also included a Benthos altimeter, which ceased functioning during the latter part of the cruise and was replaced with a Valeport altimeter, and a Seapoint turbidity sensor. Instrument Name: CTD Sea-Bird SBE 911plus Instrument Short Name:CTD SBE 911plus Instrument Description: The Sea-Bird SBE 911 plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911 plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 plus and SBE 11 plus is called a SBE 911 plus. The SBE 9 plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 plus and SBE 4). The SBE 9 plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0058/
Towfish
Towfish
PI Supplied Instrument Name: Towfish PI Supplied Instrument Description:Towfish: Seawater samples were collected with a custom surface sampling system, "towfish" comprised of acid cleaned PFA Teflon tubing and a Teflon diaphragm pump. Instrument Name: GeoFish Towed near-Surface Sampler Instrument Short Name:GeoFish Instrument Description: The GeoFish towed sampler is a custom designed near surface (2 meters or less) sampling system for the collection of trace metal clean seawater. It consists of a PVC encapsulated lead weighted torpedo and separate PVC depressor vane supporting the intake utilizing all PFA Teflon tubing connected to a deck mounted, air-driven, PFA Teflon dual-diaphragm pump which provides trace-metal clean seawater at up to 3.7L/min. The GeoFish is towed at up to 13kts off to the side of the vessel outside of the ship's wake to avoid possible contamination from the ship's hull. It was developed by Geoffrey Smith and Ken Bruland (University of California, Santa Cruz). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/31/
General Oceanics 12-L GO-FLO bottle
General Oceanics 12-L GO-FLO bottle
PI Supplied Instrument Name: General Oceanics 12-L GO-FLO bottle PI Supplied Instrument Description:General Oceanics 12-L GO-FLO bottle samplers were used with the rosette system for trace metal clean seawater collection from depth profiles. Instrument Name: GO-FLO Bottle Instrument Short Name:GO-FLO Instrument Description: GO-FLO bottle cast used to collect water samples for pigment, nutrient, plankton, etc. The GO-FLO sampling bottle is specially designed to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/30/
Metrohm VA 797
Metrohm VA 797
PI Supplied Instrument Name: Metrohm VA 797 PI Supplied Instrument Description:Metrohm VA 797 Computrace equipped with a hanging mercury drop electrode was used to measure Fe bound to humic like substances and total Fe binding capacity of humic like substances. Instrument Name: Metrohm 797 VA Computrace voltammetry system Instrument Short Name:Metrohm 797 VA Instrument Description: A computer-controlled voltammetric measuring stand with built-in potentiostat and galvanostat. Applications include voltammetric trace analysis of metal ions and other substances, and Cyclic Voltammetric Stripping (CVS) for the determination of additives in electroplating baths. Operation of the 797 VA Computrace Stand follows the potentiostatic 3-electrode principle in which the voltage of the working mercury electrode is controlled by means of a virtually currentless Ag/AgCl reference electrode to the preset desired value and the current flows across a separate platinum auxiliary electrode. The pneumatically operated Multi-Mode Electrode (MME) can operate in Hanging Mercury Drop Electrode (HMDE), Dropping Mercury Electrode (DME), or Static Mercury Drop Electrode (SMDE) modes. A Rotating Disk Electrode with exchangeable electrode tips can be used in place of the MME. Additional accessories such as autosamplers and sample processors allow for full automation of analysis, and a range of accessory kits are available to extend the range of applications. The instrument supports over 220 analytical methods.
Cruise: NBP2401
NBP2401
Community Standard Description
International Council for the Exploration of the Sea
RVIB Nathaniel B. Palmer
vessel
NBP2401
Peter N. Sedwick
Old Dominion University
https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/nathanielbpalmer_nbp2401.pdf
Report describing NBP2401
Community Standard Description
International Council for the Exploration of the Sea
RVIB Nathaniel B. Palmer
vessel