http://lod.bco-dmo.org/id/dataset/997130
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
2026-04-21
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
N2 Fixation Rates Collected on STINGI and STINGII Cruises aboard the R/V Atlantic Explorer, cruise AE2305, and the R/V Endeavor, cruise EN704, on the West Florida Shelf
2026-05-11
publication
2026-05-11
revision
Woods Hole Oceanographic Institution (WHOI BCO-DMO)
2026-05-22
publication
https://doi.org/10.26008/1912/bco-dmo.997130.1
Phoebe Dreux Chappell
University of South Florida
principalInvestigator
Rene Maurice Boiteau
Oregon State University
principalInvestigator
Kristen Nicolle Buck
Oregon State University
principalInvestigator
Timothy M. Conway
University of South Florida
principalInvestigator
Angela N. Knapp
Florida State University
principalInvestigator
Chris Smith
United States Geological Survey
principalInvestigator
Joseph Tamborski
Old Dominion 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: Chappell, P. D., Knapp, A. N., Buck, K. N., Boiteau, R. M., Conway, T. M., Smith, C., Tamborski, J., Confesor, K. (2026) N2 Fixation Rates Collected on STINGI and STINGII Cruises aboard the R/V Atlantic Explorer, cruise AE2305, and the R/V Endeavor, cruise EN704, on the West Florida Shelf. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-05-11 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.997130.1 [access date]
STING N2 Fixation Rates AE2305 and EN704 Dataset Description: Methods and Sampling: <p>Cruises STING I and STING II were conducted in Feb and July of 2023 along the&nbsp;West Florida Shelf (WFS),&nbsp;a coastal oligotrophic region characterized by low inorganic nutrient concentrations. Water was collected using&nbsp;towfish, stationary teflon pump, and ctd.&nbsp;</p>
<p>To measure <sup>15</sup>N<sub>2</sub> uptake, triplicate polycarbonate bottles (0.5-4.5 L) were rinsed with whole water then filled, ensuring that no bubbles remained. <sup>15</sup>N<sub>2</sub> gas (~99%, Cambridge Isotope Laboratories) was added using a gas-tight syringe (VICI Precision Sampling) through a flexible silicon septa; samples were gently rocked for 15 min as described by Selden et al. (2019). Any remaining bubble was subsequently removed to ensure constant isotopic enrichment over the incubation period, and bottles were incubated on-deck for approximately 24 hours. On-deck incubators were constructed from clear acrylic and covered with two layers of screening to reduce light to approximately surface seawater conditions and were plumbed with flowing surface seawater to maintain temperature. Triplicate initial PN and N isotope samples (0.5-4.5 L) were vacuum-filtered from whole water onto 25 mm GF/F (nominal pore size 0.7 µm) pre-combusted (450 <sup>o</sup>C for 2 hours) filters and frozen at -20 <sup>o</sup>C until pelletizing and analysis.&nbsp; &nbsp;</p>
<p>At the end of the incubation period, a 6 ml sample aliquot was collected from each bottle and transferred to a helium-purged Exetainer<sup>TM</sup> to which 50 μl zinc chloride (50% w/v) was added. These samples were stored at room temperature, upside down, in 15 ml Falcon<sup>TM</sup> tubes, submerged in ultrapure water, until analysis at the UC Davis Stable Isotope Facility using a ThermoScientific GasBench + Precon gas concentration system interfaced to a ThermoScientific Delta V Plus isotope-ratio mass spectrometer. The remaining incubation volume was then filtered as described above for initial PN samples. All PN samples were dried at 50 <sup>o</sup>C at least overnight and for no longer than a week. Once dry, the filters were pelletized into 30 mm-diameter tin disks (EA Consumables). Enriched and non-enriched pelletized samples were stored in separate dedicated desiccators until analysis. Initial and final incubation blank PN isotopic composition and concentration were analyzed at the University of South Florida on a Thermo Delta+XL IRMS w/ continuous-flow inlet coupled to a Carlo-Erba 1108 EA for NC isotope (15N, 13C) analysis. Final enriched PN isotopic composition and concentration samples were analyzed at the UC Davis Stable Isotope Facility using their Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced with a PDZ Europa 20-20 isotope ratio mass spectrometer. Low mass samples (&lt;10 µg N) were excluded from downstream analysis as IRMS response can become non-linear at low mass (White et al., 2020).&nbsp;</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2148836 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2148836
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2149091 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2149091
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2148989 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2148989
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2148812 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2148812
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2341997 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2341997
completed
Phoebe Dreux Chappell
University of South Florida
USF St. Petersburg campus 140 7th Ave. South
St. Petersburg
FL
33701
USA
dreux@usf.edu
pointOfContact
Rene Maurice Boiteau
Oregon State University
612-625-6983
228 Smith Hall 207 Pleasant Street Se
Minneapolis
MN
55455
USA
rboiteau@umn.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
Timothy M. Conway
University of South Florida
727-258-1081
College of Marine Sciences 830 1st St SE
St. Petersburg
FL
33701
USA
tmconway@usf.edu
pointOfContact
Angela N. Knapp
Florida State University
(979) 862-5235
797 Lamar St. Dept of Oceanography, Eller O&M Room 1204
College Station
TX
77843
USA
aknapp@tamu.edu
pointOfContact
Chris Smith
United States Geological Survey
727-510-9884
600 4th St. S.
St. Petersburg
FL
33701
USA
cgsmith@usgs.gov
pointOfContact
Joseph Tamborski
Old Dominion University
631-790-1579
339 Oceanography & Physics Bldg
Norfolk
VA
23529
USA
jtambors@odu.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Cruise
DateTime_local_Eastern
DateTime_UTC
STING_ID
Station
Depth
Lat
Lon
Collection
Type
NFixSampleNum
APN_t0
FLAG_APN_t0
vol
PN_tf_nM
APN_tf
Inc_length_d
AN2
AN2_flag
SUR_d
SUR_LOD_d
SUR_LOQ_d
SUR_Flag
NFR_nmolNLd
NFR_LOD_nmolNLd
NFR_LOQ_nmolNLd
NFR_Flag
NfixSTING_ID
Carlo-Erba 1108 EA
TMCTD
Elementar Vario EL Cube or Micro Cube elemental analyzer
PDZ Europa 20-20 isotope ratio mass spectrometer
stationary teflon pump
ThermoScientific Delta V Plus isotope-ratio mass spectrometer
Thermo Delta+XL IRMS
ThermoScientific GasBench + Precon gas concentration system
towfish
TMCTD
theme
None, User defined
Cruise identifier
ISO_DateTime_Local
ISO_DateTime_UTC
sample identification
station
depth
latitude
longitude
cast type
sample type
type of sediment trap
flag
volume
Total Particulate Nitrogen
15N, stable isotope of N
incubation time or duration
Nitrogen
No BCO-DMO term
nitrogen fixation rate
featureType
BCO-DMO Standard Parameters
Carlo-Erba EA-1108 elemental analyzer
CTD - profiler
Elementar Vario EL Cube elemental analyzer
PDZ Europa 20-20 isotope ratio mass spectrometer
Pump
Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer
Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer
Thermo-Fisher Scientific Gas Bench II
towed unmanned submersible
Trace Metal Bottle
instrument
BCO-DMO Standard Instruments
AE2305
EN704
service
Deployment Activity
Gulf of Mexico near Florida
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.
Collaborative Research: Linking iron and nitrogen sources in an oligotrophic coastal margin: Nitrogen fixation and the role of boundary fluxes
https://osprey.bco-dmo.org/project/880516
Collaborative Research: Linking iron and nitrogen sources in an oligotrophic coastal margin: Nitrogen fixation and the role of boundary fluxes
<p><strong>NSF Award Abstract:</strong><br />
This project will investigate how groundwater discharge delivers important nutrients to the coastal ecosystems of the West Florida Shelf. Preliminary studies indicate that groundwater may supply both dissolved organic nitrogen (DON) and iron in this region. In coastal ecosystems like the West Florida Shelf that have very low nitrate and ammonium concentrations, DON is the main form of nitrogen available to organisms. Nitrogen cycling is strongly affected by iron availability because iron is essential for both photosynthesis and for nitrogen fixation. This study will investigate the sources and composition of DON and iron, and their influence on the coastal ecosystem. The team will sample offshore groundwater wells, river and estuarine waters, and conduct two expeditions across the West Florida Shelf in winter and summer. Investigators will participate in K-12 and outreach activities to increase awareness of the project and related science. The project will fund the work of six graduate and eight undergraduate students across five institutions, furthering NSF’s goals of education and training.</p>
<p>Motivated by preliminary observations of unexplained, tightly-correlated DON and dissolved iron concentrations across the West Florida Shelf (WFS), the proposed work will quantify the flux and isotopic signatures of submarine groundwater discharge (SGD)-derived DON and iron to the WFS, and evaluate the bioavailability of this temporally-variable source using four seasonal near-shore campaigns sampling offshore groundwater wells, estuarine, and riverine endmembers and two cross-shelf cruises. The work will evaluate whether SGD stimulates nitrogen fixation on the WFS, and the potential for the stimulated nitrogen fixation to further modify the chemistry of DON and dissolved iron in the region. The cross-shelf cruises will investigate hypothesized periods of maximum SGD and Trichodesmium abundance (June), and reduced river discharge and SGD (February), thus comparing two distinct biogeochemical regimes. The concentrations and isotopic compositions of DON and dissolved iron, molecular composition of DON, and the concentration and composition of iron-binding ligands will be characterized. Nitrogen fixation rates and Trichodesmium spp. abundance and expression of iron stress genes will be measured. Fluxes of DON and iron from SGD and rivers will be quantified with radium isotope mass balances. The impacts of SGD on nitrogen fixation and DON/ligand production will be constrained with incubations of natural phytoplankton communities with submarine groundwater amendments. Two hypotheses will be tested: 1) SGD is the dominant source of bioavailable DON and dissolved iron on the WFS, and 2) SGD-alleviation of iron stress changes the dominant Trichodesmium species on the WFS, increases nitrogen fixation rates and modifies DON and iron composition. Overall, the work will establish connections between marine nitrogen and iron cycling and evaluate the potential for coastal inputs to modify water along the WFS before export to the Atlantic Ocean. This study will thus provide a framework to consider these boundary fluxes in oligotrophic coastal systems and the relative importance of rivers and SGD as sources of nitrogen and iron in other analogous locations, such as coastal systems in Australia, India, and Africa, where nitrogen fixation and SGD have also been documented.</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>
West Florida Shelf DON and Fe
largerWorkCitation
project
eng; USA
oceans
Gulf of Mexico near Florida
-86.566932
-82.515283
26.140667
28.498467
2023-02-20
2023-07-12
Gulf of Mexico/America, West Florida Shelf
0
BCO-DMO catalogue of parameters from N2 Fixation Rates Collected on STINGI and STINGII Cruises aboard the R/V Atlantic Explorer, cruise AE2305, and the R/V Endeavor, cruise EN704, on the West Florida Shelf
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/999116.rdf
Name: Cruise
Units: unitless
Description: <p>Which cruise sample was collected: STINGI or STINGII</p>
http://lod.bco-dmo.org/id/dataset-parameter/999117.rdf
Name: DateTime_local_Eastern
Units: unitless
Description: <p>Datetime of sampling (beginning incubation) in Eastern Standard/Daylight Savings Time</p>
http://lod.bco-dmo.org/id/dataset-parameter/999118.rdf
Name: DateTime_UTC
Units: unitless
Description: <p>Datetime of sampling (beginning incubation) in UTC</p>
http://lod.bco-dmo.org/id/dataset-parameter/999120.rdf
Name: STING_ID
Units: unitless
Description: <p>Project specific identification number, which is unique to each sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/999121.rdf
Name: Station
Units: unitless
Description: <p>Station identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/999122.rdf
Name: Depth
Units: meters
Description: <p>depth of sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/999124.rdf
Name: Lat
Units: decimal degrees
Description: <p>Latitude of sampling site</p>
http://lod.bco-dmo.org/id/dataset-parameter/999126.rdf
Name: Lon
Units: decimal degrees
Description: <p>Longitude of sampling site</p>
http://lod.bco-dmo.org/id/dataset-parameter/999128.rdf
Name: Collection
Units: unitless
Description: <p>The method of collection for the incubated water sample, where fish = towfish, koubapump = stationary teflon pump, TMCTD = trace metal CTD</p>
http://lod.bco-dmo.org/id/dataset-parameter/999129.rdf
Name: Type
Units: unitless
Description: <p>type of sample collection, where surface = surface, chl max = chlorophyll maximum</p>
http://lod.bco-dmo.org/id/dataset-parameter/999130.rdf
Name: NFixSampleNum
Units: unitless
Description: <p>Lab specific identification number which is unique to each N2 fixation incubation</p>
http://lod.bco-dmo.org/id/dataset-parameter/999131.rdf
Name: APN_t0
Units: atom %
Description: <p>Mean atom% 15N enrichment at initial timepoint</p>
http://lod.bco-dmo.org/id/dataset-parameter/999132.rdf
Name: FLAG_APN_t0
Units: unitless
Description: <p>Flag for APN_t0 value used in specific uptake rate/N2 fixation rate calculation, where IB = APN_IB used instead of APN_T0; 2RepT0 = APN_T0 only came from 2 replicates.</p>
http://lod.bco-dmo.org/id/dataset-parameter/999133.rdf
Name: vol
Units: liters
Description: <p>Volume of water used for 15N2 incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/999134.rdf
Name: PN_tf_nM
Units: nanomolar
Description: <p>Particulate nitrogen concentration of sample water at Tf</p>
http://lod.bco-dmo.org/id/dataset-parameter/999135.rdf
Name: APN_tf
Units: atom %
Description: <p>Atom% 15N enrichment at final time point</p>
http://lod.bco-dmo.org/id/dataset-parameter/999136.rdf
Name: Inc_length_d
Units: days
Description: <p>Length of time for 15N2 incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/999137.rdf
Name: AN2
Units: atom %
Description: <p>Atom% 15N enrichment of N2 pool in incubation bottle; subsampled at final time point</p>
http://lod.bco-dmo.org/id/dataset-parameter/999138.rdf
Name: AN2_flag
Units: unitless
Description: <p>Flag indicating whether a subsample to directly determine 15N enrichment of the N2 pool in the specific incubation bottle was analyzed; NO_AN2_SPL_RUN indicates that the sample was lost, damaged, or otherwise unable to be analyzed, in which case this value is the average from all runs</p>
http://lod.bco-dmo.org/id/dataset-parameter/999139.rdf
Name: SUR_d
Units: per day
Description: <p>Specific N2 uptake rate calculated from replicate incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/999140.rdf
Name: SUR_LOD_d
Units: per day
Description: <p>Limit of detection for specific N2 uptake rate at given sampling location</p>
http://lod.bco-dmo.org/id/dataset-parameter/999141.rdf
Name: SUR_LOQ_d
Units: per day
Description: <p>Limit of quantification for specific N2 uptake rate at given sampling location</p>
http://lod.bco-dmo.org/id/dataset-parameter/999142.rdf
Name: SUR_Flag
Units: unitless
Description: <p>Flag for specific uptake rate, where DNQ = Detected but not quantifiable; BDL = Below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/999143.rdf
Name: NFR_nmolNLd
Units: nanomoles nitrogen per liter per day
Description: <p>N2 fixation rate calculated from replicate incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/999144.rdf
Name: NFR_LOD_nmolNLd
Units: nanomoles nitrogen per liter per day
Description: <p>Limit of detection for N2 fixation rate at given sampling location</p>
http://lod.bco-dmo.org/id/dataset-parameter/999145.rdf
Name: NFR_LOQ_nmolNLd
Units: nanomoles nitrogen per liter per day
Description: <p>Limit of quantification for N2 fixation rate at given sampling location</p>
http://lod.bco-dmo.org/id/dataset-parameter/999146.rdf
Name: NFR_Flag
Units: unitless
Description: <p>Flag for N2 fixation rate, where DNQ = Detected but not quantifiable; BDL = Below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/999147.rdf
Name: NfixSTING_ID
Units: unitless
Description: <p>Measurement specific sample identification number which is unique to each individual measurement and distinct from the STING ID that is sample/project specific</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
https://doi.org/10.26008/1912/bco-dmo.997130.1
download
onLine
dataset
<p>Cruises STING I and STING II were conducted in Feb and July of 2023 along the&nbsp;West Florida Shelf (WFS),&nbsp;a coastal oligotrophic region characterized by low inorganic nutrient concentrations. Water was collected using&nbsp;towfish, stationary teflon pump, and ctd.&nbsp;</p>
<p>To measure <sup>15</sup>N<sub>2</sub> uptake, triplicate polycarbonate bottles (0.5-4.5 L) were rinsed with whole water then filled, ensuring that no bubbles remained. <sup>15</sup>N<sub>2</sub> gas (~99%, Cambridge Isotope Laboratories) was added using a gas-tight syringe (VICI Precision Sampling) through a flexible silicon septa; samples were gently rocked for 15 min as described by Selden et al. (2019). Any remaining bubble was subsequently removed to ensure constant isotopic enrichment over the incubation period, and bottles were incubated on-deck for approximately 24 hours. On-deck incubators were constructed from clear acrylic and covered with two layers of screening to reduce light to approximately surface seawater conditions and were plumbed with flowing surface seawater to maintain temperature. Triplicate initial PN and N isotope samples (0.5-4.5 L) were vacuum-filtered from whole water onto 25 mm GF/F (nominal pore size 0.7 µm) pre-combusted (450 <sup>o</sup>C for 2 hours) filters and frozen at -20 <sup>o</sup>C until pelletizing and analysis.&nbsp; &nbsp;</p>
<p>At the end of the incubation period, a 6 ml sample aliquot was collected from each bottle and transferred to a helium-purged Exetainer<sup>TM</sup> to which 50 μl zinc chloride (50% w/v) was added. These samples were stored at room temperature, upside down, in 15 ml Falcon<sup>TM</sup> tubes, submerged in ultrapure water, until analysis at the UC Davis Stable Isotope Facility using a ThermoScientific GasBench + Precon gas concentration system interfaced to a ThermoScientific Delta V Plus isotope-ratio mass spectrometer. The remaining incubation volume was then filtered as described above for initial PN samples. All PN samples were dried at 50 <sup>o</sup>C at least overnight and for no longer than a week. Once dry, the filters were pelletized into 30 mm-diameter tin disks (EA Consumables). Enriched and non-enriched pelletized samples were stored in separate dedicated desiccators until analysis. Initial and final incubation blank PN isotopic composition and concentration were analyzed at the University of South Florida on a Thermo Delta+XL IRMS w/ continuous-flow inlet coupled to a Carlo-Erba 1108 EA for NC isotope (15N, 13C) analysis. Final enriched PN isotopic composition and concentration samples were analyzed at the UC Davis Stable Isotope Facility using their Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced with a PDZ Europa 20-20 isotope ratio mass spectrometer. Low mass samples (&lt;10 µg N) were excluded from downstream analysis as IRMS response can become non-linear at low mass (White et al., 2020).&nbsp;</p>
Specified by the Principal Investigator(s)
<p>Specific N<sub>2</sub>&nbsp;uptake rates (SUR) were calculated following Montoya et al. (1996):</p>
<blockquote>
<p>SUR= [(A<sub>PN</sub>_tf -A<sub>PN</sub>_t0)/(A<sub>N2</sub> – A<sub>PN</sub>_t0)] x (1/time)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Eqn. 1</p>
</blockquote>
<p>where&nbsp;<em>A</em>&nbsp;represents the atom-% enrichment of the initial (t=0) or final (t=f) PN pool, or the N<sub>2</sub>&nbsp;pool.&nbsp;Across all experiments,&nbsp;A<sub>N2</sub>_t0 averaged 0.367&nbsp;± 0.001 %. Experiments with &lt;1% enrichment were excluded from downstream analysis. The specific uptake rate represents the relative contribution of diazotroph-derived N to PN turnover within a given sample. Absolute N<sub>2</sub>&nbsp;fixation rates (NFR) were calculated as:</p>
<blockquote>
<p>NFR= SUR x [PN]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Eqn. 2</p>
</blockquote>
<p>where [PN] indicates the PN concentration at t=f. Limits of detection and quantification were calculated per incubation by propagating the minimum detectable difference between initial and final&nbsp;<sup>15</sup>N atom-% enrichment of the PN pool (3σ&nbsp;and 10σ, respectively, n≥6 N standards between 9-16 µg N measured daily) through Eqn. 2. Station rate estimates were calculated by taking the mean of the replicate incubations. For the station rate estimates, a rate was only considered detectable if two of three replicate incubations yielded detectable rates.</p>
Specified by the Principal Investigator(s)
- Loaded sheet 1 from Excel file "STING_nfix_individual_tosubmit.xlsx" with header row 1; treated "" and "nd" as missing values
- Converted "Date-time_EST" field (format "%m/%d/%y %H:%M", Eastern timezone) to "DateTime_local_Eastern" field with output format "%Y-%m-%dT%H:%M" in Eastern timezone
- Converted "DateTime_local_Eastern" to "DateTime_UTC" with output format "%Y-%m-%dT%H:%MZ", converting from Eastern to UTC timezone
- Deleted original "Date-time_EST" field
- Renamed fields to comply with BCO-DMO naming conventions: Depth_m to Depth, Lat_degN to Lat, Lon_degW to Lon, vol_L to vol, "APN_ t0" to APN_t0
- Output written to "997130_v1_sting_nfix.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
Carlo-Erba 1108 EA
Carlo-Erba 1108 EA
PI Supplied Instrument Name: Carlo-Erba 1108 EA PI Supplied Instrument Description:Solid natural abundance samples analyzed at USF used a Thermo Delta+XL IRMS w/ continuous-flow inlet coupled to a Carlo-Erba 1108 EA Instrument Name: Carlo-Erba EA-1108 elemental analyzer Instrument Short Name:Carlo-Erba EA 1108 Instrument Description: An elemental analyzer that simultaneously determines the total carbon, hydrogen, nitrogen, and sulfur in a small solid or liquid sample. A sample is put into a tin capsule that is placed in the combustion tube. Here, the sample is in an oxygen-rich gas stream, which causes flash combustion of the tin capsule, and in turn, the sample is rapidly combusted. The resulting gases are separated on a packed gas chromatography column and quantified using a thermal conductivity detector. The instrument was originally manufactured by Carlo-Erba, which has since been replaced by Thermo Scientific (part of Thermo Fisher Scientific). This model is no longer in production. It is also possible to determine oxygen with a modification to the systems configuration. Analysis times: CHN in 7 min, S in 5 min and O in 6 min. Range: 10 ppm to 100%.
TMCTD
TMCTD
PI Supplied Instrument Name: TMCTD PI Supplied Instrument Description:The method of collection for the incubated water sample, where fish = towfish, koubapump = stationary teflon pump, TMCTD = trace metal CTD Instrument Name: CTD - profiler Instrument Short Name: Instrument Description: The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast.
This term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/130/
Elementar Vario EL Cube or Micro Cube elemental analyzer
Elementar Vario EL Cube or Micro Cube elemental analyzer
PI Supplied Instrument Name: Elementar Vario EL Cube or Micro Cube elemental analyzer PI Supplied Instrument Description:Solid enriched samples analyzed at the UC Davis Stable Isotope Facility used their Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced with a PDZ Europa 20-20 isotope ratio mass spectrometer Instrument Name: Elementar Vario EL Cube elemental analyzer Instrument Short Name:Vario EL Cube Instrument Description: A laboratory instrument used for quantifying organic elements. It can measure C, H, N and S and optionally O, Cl and TIC. It was first developed in 2006 as a successor to the vario EL III. It uses a high-temperature combustion unit that is able to complete sample digestion at up to 1200 deg C (or 1800 deg C at the point of combustion when tin foil is used) and a jet injection of oxygen directly to the sample during combustion. Separation of gas components are performed on up to 3 gas-selective columns which trap gases until they are heated up and the prior gas peak has reached the baseline during detection. It uses a Thermal Conductivity Detector (TCD) as standard. An infrared (IR) detector for sulfur and oxygen and electrochemical detector for chlorine are optionally available. The instrument can measure C / N elemental ratios of up to 12,000:1 and provides an elemental detection limit of < 40 ppm (TCD).
PDZ Europa 20-20 isotope ratio mass spectrometer
PDZ Europa 20-20 isotope ratio mass spectrometer
PI Supplied Instrument Name: PDZ Europa 20-20 isotope ratio mass spectrometer PI Supplied Instrument Description:Solid enriched samples analyzed at the UC Davis Stable Isotope Facility used their Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced with a PDZ Europa 20-20 isotope ratio mass spectrometer Instrument Name: PDZ Europa 20-20 isotope ratio mass spectrometer Instrument Short Name:Europa 20-20 IRMS Instrument Description: The PDZ Europa 20-20 is a dedicated continuous flow isotope ratio mass spectrometer for hyphenated stable isotope analyses able to measure 15N, 13C, 18O, and 34S in a host of applications. The analyzer has been purposely designed to measure 2H by continuous flow methodology and is also suitable to analyze the light stable isotopes in all the commonly measured gases: H2, N2, NO, N2O, O2, CO, CO2, SO, and SO2.
stationary teflon pump
stationary teflon pump
PI Supplied Instrument Name: stationary teflon pump PI Supplied Instrument Description:The method of collection for the incubated water sample, where fish = towfish, koubapump = stationary teflon pump, TMCTD = trace metal CTD Instrument Name: Pump Instrument Short Name: Instrument Description: A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps
ThermoScientific Delta V Plus isotope-ratio mass spectrometer
ThermoScientific Delta V Plus isotope-ratio mass spectrometer
PI Supplied Instrument Name: ThermoScientific Delta V Plus isotope-ratio mass spectrometer PI Supplied Instrument Description:Stable isotope ratios of nitrogen (δ15N) were measured at UC Davis using a ThermoScientific GasBench + Precon gas concentration system interfaced to a ThermoScientific Delta V Plus isotope-ratio mass spectrometer (Bremen, Germany). Instrument Name: Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer Instrument Short Name:Delta V Plus IRMS Instrument Description: The Thermo Scientific DELTA V Plus is an isotope ratio mass spectrometer designed to measure isotopic, elemental and molecular ratios of organic and inorganic compounds. The DELTA V Plus is an enhanced model of the DELTA V series of isotope ratio mass spectrometers, which can be upgraded from the DELTA V Advantage. The DELTA V Plus can be operated in Continuous Flow or Dual Inlet mode and can accommodate up to 10 collectors, ensuring flexibility to cover many applications. The DELTA V Plus is controlled by an automated, integrated Isodat software suite. A magnet, whose pole faces determine the free flight space for the ions, eliminates the traditional flight tube. The magnet is designed for fast mass switching which is further supported by a fast jump control between consecutive measurements of multiple gases within one run. The sample gas is introduced at ground potential, eliminating the need for insulation of the flow path, ensuring 100 percent transfer into the ion source. The amplifiers register ion beams up to 50 V. The DELTA V Plus has refined optics, enabling greater ion transmission than the DELTA V Advantage. It has a sensitivity of 800 molecules per ion (M/I) in Dual Inlet mode and 1100 M/I in Continuous Flow mode. It has a system stability of < 10 ppm and an effective magnetic detection radius of 191 nm. It has a mass range of 1 - 96 Dalton at 3 kV.
Thermo Delta+XL IRMS
Thermo Delta+XL IRMS
PI Supplied Instrument Name: Thermo Delta+XL IRMS PI Supplied Instrument Description:Solid natural abundance samples analyzed at USF used a Thermo Delta+XL IRMS w/ continuous-flow inlet coupled to a Carlo-Erba 1108 EA Instrument Name: Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer Instrument Short Name:Delta V Plus IRMS Instrument Description: The Thermo Scientific DELTA V Plus is an isotope ratio mass spectrometer designed to measure isotopic, elemental and molecular ratios of organic and inorganic compounds. The DELTA V Plus is an enhanced model of the DELTA V series of isotope ratio mass spectrometers, which can be upgraded from the DELTA V Advantage. The DELTA V Plus can be operated in Continuous Flow or Dual Inlet mode and can accommodate up to 10 collectors, ensuring flexibility to cover many applications. The DELTA V Plus is controlled by an automated, integrated Isodat software suite. A magnet, whose pole faces determine the free flight space for the ions, eliminates the traditional flight tube. The magnet is designed for fast mass switching which is further supported by a fast jump control between consecutive measurements of multiple gases within one run. The sample gas is introduced at ground potential, eliminating the need for insulation of the flow path, ensuring 100 percent transfer into the ion source. The amplifiers register ion beams up to 50 V. The DELTA V Plus has refined optics, enabling greater ion transmission than the DELTA V Advantage. It has a sensitivity of 800 molecules per ion (M/I) in Dual Inlet mode and 1100 M/I in Continuous Flow mode. It has a system stability of < 10 ppm and an effective magnetic detection radius of 191 nm. It has a mass range of 1 - 96 Dalton at 3 kV.
ThermoScientific GasBench + Precon gas concentration system
ThermoScientific GasBench + Precon gas concentration system
PI Supplied Instrument Name: ThermoScientific GasBench + Precon gas concentration system PI Supplied Instrument Description:Stable isotope ratios of nitrogen (δ15N) were measured at UC Davis using a ThermoScientific GasBench + Precon gas concentration system interfaced to a ThermoScientific Delta V Plus isotope-ratio mass spectrometer (Bremen, Germany). Instrument Name: Thermo-Fisher Scientific Gas Bench II Instrument Short Name:GasBench II Instrument Description: An on-line gas preparation and introduction system for isotope ratio mass spectrometry that is designed for high precision isotope and molecular ratio determination of headspace samples, including water equilibration, carbonates and atmospheric gases. The instrument allows for the use of a dual viscous flow inlet system of repetitive measurements of sample and standard gas on a continuous flow isotope ratio mass spectrometer (CF-IRMS) system. The sample volume is the sample vial (instead of a metal bellows), and the reference gas volume is a pressurized gas tank. The instrument consists of a user programmable autosampler, a gas sampling system, a maintenance-free water removal system, a loop injection system, an isothermal gas chromatograph (GC), an active open split interface, a reference gas injection system with three reference ports, and one or two optional LN2 traps for cryofocusing. The gas sampling system includes a two port needle which adds a gentle flow of He into the sample vial, diluting and displacing sample gas. Water is removed from the sample gas through diffusion traps. The loop injector aliquots the sample gas onto the GC column, which separates the molecular species. The reference gas injection system allows accurate referencing of each sample aliquot to isotopic standards. The system can be used with several options including a carbonate reaction kit that allows injection of anhydrous phospohric acid into sample vials.
Note "Finnigan GasBench-II" is the previous brand name of this instrument.
towfish
towfish
PI Supplied Instrument Name: towfish PI Supplied Instrument Description:The method of collection for the incubated water sample, where fish = towfish, koubapump = stationary teflon pump, TMCTD = trace metal CTD Instrument Name: towed unmanned submersible Instrument Short Name:towed unmanned submersible Instrument Description: A vehicle towed by rigid cable through the water column at fixed or varying depth with no propulsion and no human operator (e.g. Towfish, Scanfish, UOR, SeaSoar).
TMCTD
TMCTD
PI Supplied Instrument Name: TMCTD PI Supplied Instrument Description:The method of collection for the incubated water sample, where fish = towfish, koubapump = stationary teflon pump, TMCTD = trace metal CTD Instrument Name: Trace Metal Bottle Instrument Short Name:TM Bottle Instrument Description: Trace metal (TM) clean rosette bottle used for collecting trace metal clean seawater samples. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/30/
Cruise: AE2305
AE2305
R/V Atlantic Explorer
Community Standard Description
International Council for the Exploration of the Sea
R/V Atlantic Explorer
vessel
AE2305
Angela N. Knapp
Florida State University
Cruise: EN704
EN704
R/V Endeavor
Community Standard Description
International Council for the Exploration of the Sea
R/V Endeavor
vessel
EN704
Angela N. Knapp
Florida State University
R/V Atlantic Explorer
Community Standard Description
International Council for the Exploration of the Sea
R/V Atlantic Explorer
vessel
R/V Endeavor
Community Standard Description
International Council for the Exploration of the Sea
R/V Endeavor
vessel