http://lod.bco-dmo.org/id/dataset/3913
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
2013-04-15
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
delta 15N of nitrate from R/V Knorr cruise KN199-04 & KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011 (U.S. GEOTRACES NAT project)
2013-04-29
publication
2013-04-29
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2020-03-31
publication
https://doi.org/10.26008/1912/bco-dmo.3913.1
Karen L. Casciotti
Stanford University
principalInvestigator
Daniel M. Sigman
Princeton 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: Casciotti, K., Sigman, D. (2020) delta 15N of nitrate from R/V Knorr cruise KN199-04 & KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011 (U.S. GEOTRACES NAT project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2013-04-29 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.3913.1 [access date]
delta 15N of nitrate from GT10 and GT11 cruises. Dataset Description: <p>Dataset includes delta 15N of nitrate (NO3) measurements from the GT10 and GT11 (KN199-04 and KN204-01) U.S. GEOTRACES North Atlantic Transect cruises.</p> Methods and Sampling: <p><strong>Sampling:</strong><br />
Full depth and super station samples were collected from the ship's rosette. Samples were filtered through 0.8/0.45 um acropak500 filter cartridges into triple-rinsed 60 mL HDPE bottles. Demi station samples were collected from the GEOTRACES Go-Flo rosette. Samples were filtered through 0.2 um acropak capsule filters into triple-rinsed 60 mL HDPE bottles. Each sample was collected in triplicate. Samples were frozen at -20 C immediately and stored frozen until analysis.</p>
<p><strong>Analysis:</strong><br />
Samples were analyzed for nitrate d15N and d18O using the denitrifier method (Sigman et al., 2001; Casciotti, et al., 2001, with technical updates described by McIlvin and Casciotti, 2011). Nitrate isotope reference materials USGS32, USGS34, and USGS35 were used to calibrate d18O and USGS32 and USGS34 to calibrate d15N. Each sample was analyzed 2-6 times. Mean and standard deviations are reported for each sample. All samples were analyzed on a DeltaPLUS XP isotope ratio mass spectrometer, with custom-built inlet described in McIlvin and Casciotti, 2011.</p>
<p>Where possible (concentrations exceeded 2 uM), samples and standards were analyzed in 20 nanomole aliquots. When NO3- concentrations were below 2 uM, samples were injected in maximum volume (10 mL) and calibrated using interpolations between standard curves of 5 and 20 nano moles NO3-. Some samples contained nitrate concentrations lower than the typical analytical window (300 nM NO3-), but were analyzed nonetheless. Samples analyzed with concentrations below 0.3 uM are were flagged as "low concentration". These samples contained a subset with major ion peak areas (m/z 44) less than 1 volt-second, which are flagged at "low area". Two of these samples are flagged as having elevated d18O-NO3 values relative to their d15N-NO3 values. The flagged samples should be treated with caution.</p>
<p>This version (16 March 2013) has not been thoroughly intercalibrated with data from the Sigman Lab. Currently, there exists no detachable d15N offset between the datasets. However, Casciotti d18O data are approximately 0.6 permil higher than Sigman d18O data.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1138360 Award URL: http://nsf.gov/awardsearch/showAward?AWD_ID=1138360
completed
Karen L. Casciotti
Stanford University
650-721-5545
Department of Environmental Earth System Science 473 Via Ortega, Y2E2 Building, Room 140
Stanford
CA
94305
USA
kcasciotti@stanford.edu
pointOfContact
Daniel M. Sigman
Princeton University
609-258-2194
Department of Geosciences M52 Guyot Hall
Princeton
NJ
08544
USA
sigman@princeton.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
cruise_id
station_GEOTRC
depth_GEOTRC_CTD
press
event_GEOTRC
cast_GEOTRC
sample_GEOTRC
sample_bottle_GEOTRC
bottle_GEOTRC
month_gmt
day_gmt
year
time_gmt
lat
lon
d15N_NO3
d15N_NO3_sd
n
flag_low_area
flag_low_conc
ISO_DateTime_UTC
BTL_ISO_DateTime_UTC
GO-FLO Bottle
Niskin bottle
Isotope-ratio Mass Spectrometer
theme
None, User defined
cruise id
station
depth
water pressure
event
cast
sample identification
Niskin bottle number
bottle
month_gmt
day_gmt
year
time_gmt
latitude
longitude
dN15_NO3
standard deviation
numb_obs
quality flag
ISO_DateTime_UTC
featureType
BCO-DMO Standard Parameters
GO-FLO Bottle
Niskin bottle
Isotope-ratio Mass Spectrometer
instrument
BCO-DMO Standard Instruments
KN199-04
KN204-01
service
Deployment Activity
Subtropical northern Atlantic Ocean
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
U.S. GEOTRACES North Atlantic Transect (GA03)
https://www.geotraces.org/
U.S. GEOTRACES North Atlantic Transect (GA03)
<p><em>Much of this text appeared in an article published in OCB News, October 2008, by the OCB Project Office.</em></p>
<p>The first U.S. GEOTRACES Atlantic Section will be specifically centered around a sampling cruise to be carried out in the North Atlantic in 2010. Ed Boyle (MIT) and Bill Jenkins (WHOI) organized a three-day planning workshop that was held September 22-24, 2008 at the Woods Hole Oceanographic Institution. The main goal of the workshop, sponsored by the National Science Foundation and the U.S. GEOTRACES Scientific Steering Committee, was to design the implementation plan for the first U.S. GEOTRACES Atlantic Section. The primary cruise design motivation was to improve knowledge of the sources, sinks and internal cycling of Trace Elements and their Isotopes (TEIs) by studying their distributions along a section in the North Atlantic (Figure 1). The North Atlantic has the full suite of processes that affect TEIs, including strong meridional advection, boundary scavenging and source effects, aeolian deposition, and the salty Mediterranean Outflow. The North Atlantic is particularly important as it lies at the "origin" of the global Meridional Overturning Circulation.</p>
<p>It is well understood that many trace metals play important roles in biogeochemical processes and the carbon cycle, yet very little is known about their large-scale distributions and the regional scale processes that affect them. Recent advances in sampling and analytical techniques, along with advances in our understanding of their roles in enzymatic and catalytic processes in the open ocean provide a natural opportunity to make substantial advances in our understanding of these important elements. Moreover, we are motivated by the prospect of global change and the need to understand the present and future workings of the ocean's biogeochemistry. The GEOTRACES strategy is to measure a broad suite of TEIs to constrain the critical biogeochemical processes that influence their distributions. In addition to these "exotic" substances, more traditional properties, including macronutrients (at micromolar and nanomolar levels), CTD, bio-optical parameters, and carbon system characteristics will be measured. The cruise starts at Line W, a repeat hydrographic section southeast of Cape Cod, extends to Bermuda and subsequently through the North Atlantic oligotrophic subtropical gyre, then transects into the African coast in the northern limb of the coastal upwelling region. From there, the cruise goes northward into the Mediterranean outflow. The station locations shown on the map are for the "fulldepth TEI" stations, and constitute approximately half of the stations to be ultimately occupied.</p>
<p><em>Figure 1. The proposed 2010 Atlantic GEOTRACES cruise track plotted on dissolved oxygen at 400 m depth. Data from the World Ocean Atlas (Levitus et al., 2005) were plotted using Ocean Data View (courtesy Reiner Schlitzer). [click on the image to view a larger version]</em><br /><a href="/objectserver/86c47ca3173d90ef5edcec249de05aa6/GEOTRACES_Atl_stas.jpg?url=http%3A%2F%2Fbcodata.whoi.edu%2FUS_GEOTRACES%2FAtlanticSection%2FGEOTRACES_Atl_stas.jpg&f=3163653666383833383364633438646666303638356339386633613165393232687474703a2f2f62636f646174612e77686f692e6564752f55535f47454f5452414345532f41746c616e74696353656374696f6e2f47454f5452414345535f41746c5f737461732e6a7067" target="_blank"><img alt="" src="https://datadocs.bco-dmo.org/d2/US_GEOTRACES/AtlanticSection/GEOTRACES_Atl_stas.jpg" style="width:350px" /></a></p>
<p>Hydrography, CTD and nutrient measurements will be supported by the Ocean Data Facility (J. Swift) at Scripps Institution of Oceanography and funded through NSF Facilities. They will be providing an additional CTD rosette system along with nephelometer and LADCP. A trace metal clean Go-Flo Rosette and winch will be provided by the group at Old Dominion University (G. Cutter) along with a towed underway pumping system.</p>
<p>The North Atlantic Transect cruise began in 2010 with KN199 leg 4 (station sampling) and leg 5 (underway sampling only) (Figure 2).</p>
<p><a href="http://bcodata.whoi.edu//US_GEOTRACES/AtlanticSection/Cruise_Report_for_Knorr_199_Final_v3.pdf" target="_blank">KN199-04 Cruise Report (PDF)</a></p>
<p><em>Figure 2. The red line shows the cruise track for the first leg of the US Geotraces North Atlantic Transect on the R/V Knorr in October 2010. The rest of the stations (beginning with 13) will be completed in October-December 2011 on the R/V Knorr (courtesy of Bill Jenkins, Chief Scientist, GNAT first leg). [click on the image to view a larger version]</em><br /><a href="/objectserver/28028490f13f23fe63a08ff289a7cc8a/GNAT_stationPlan.jpg?url=http%3A%2F%2Fbcodata.whoi.edu%2FUS_GEOTRACES%2FAtlanticSection%2FGNAT_stationPlan.jpg&f=3837393231613337386638616637626663373565643337316231306231363634687474703a2f2f62636f646174612e77686f692e6564752f55535f47454f5452414345532f41746c616e74696353656374696f6e2f474e41545f73746174696f6e506c616e2e6a7067" target="_blank"><img alt="Atlantic Transect Station location map" src="https://datadocs.bco-dmo.org/d2/US_GEOTRACES/AtlanticSection/GNAT_stationPlan_sm.jpg" style="width:350px" /></a></p>
<p>The section completion effort resumed again in November 2011 with KN204-01A,B (Figure 3).</p>
<p><a href="http://bcodata.whoi.edu//US_GEOTRACES/AtlanticSection/Submitted_Preliminary_Cruise_Report_for_Knorr_204-01.pdf" target="_blank">KN204-01A,B Cruise Report (PDF)</a></p>
<p><em>Figure 3. Station locations occupied on the US Geotraces North Atlantic Transect on the R/V Knorr in November 2011. [click on the image to view a larger version]</em><br /><a href="/objectserver/008fd0c21f8a23724741e9c150458427/KN204-01_Stations.png?url=http%3A%2F%2Fbcodata.whoi.edu%2FUS_GEOTRACES%2FAtlanticSection%2FKN204-01_Stations.png&f=6633373930333834633833323933666666326139613061306266336237306638687474703a2f2f62636f646174612e77686f692e6564752f55535f47454f5452414345532f41746c616e74696353656374696f6e2f4b4e3230342d30315f53746174696f6e732e706e67" target="_blank"><img alt="Atlantic Transect/Part 2 Station location map" src="https://datadocs.bco-dmo.org/d2/US_GEOTRACES/AtlanticSection/KN204-01_Stations.png" style="width:350px" /></a></p>
<p>Data from the North Atlantic Transect cruises are available under the Datasets heading below, and consensus values for the SAFe and North Atlantic GEOTRACES Reference Seawater Samples are available from the GEOTRACES Program Office: <a href="http://www.geotraces.org/science/intercalibration/322-standards-and-reference-materials?acm=455_215" target="_blank">Standards and Reference Materials</a></p>
<p><strong>ADCP data</strong> are available from the Currents ADCP group at the University of Hawaii at the links below:<br /><a href="http://currents.soest.hawaii.edu/uhdas_adcp/year2010.html#kn199_4" target="_blank">KN199-04</a> (leg 1 of 2010 cruise; Lisbon to Cape Verde)<br /><a href="http://currents.soest.hawaii.edu/uhdas_adcp/year2010.html#kn199_5" target="_blank">KN199-05</a> (leg 2 of 2010 cruise; Cape Verde to Charleston, NC)<br /><a href="http://currents.soest.hawaii.edu/uhdas_adcp/year2011.html#kn204_01" target="_blank">KN204-01A</a> (part 1 of 2011 cruise; Woods Hole, MA to Bermuda)<br /><a href="http://currents.soest.hawaii.edu/uhdas_adcp/year2011.html#kn204_02" target="_blank">KN204-01B</a> (part 2 of 2011 cruise; Bermuda to Cape Verde)</p>
U.S. GEOTRACES NAT
largerWorkCitation
project
eng; USA
oceans
Subtropical northern Atlantic Ocean
-69.8644
-9.6601
17.3497
39.7014
2010-10-16
2011-12-10
Subtropical western and eastern North Atlantic Ocean (GA03)
0
BCO-DMO catalogue of parameters from delta 15N of nitrate from R/V Knorr cruise KN199-04 & KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011 (U.S. GEOTRACES NAT 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
http://lod.bco-dmo.org/id/dataset-parameter/34038.rdf
Name: cruise_id
Units: text
Description: Official cruise identifier e.g. KN199-04 = R/V Knorr cruise number 199-04.
http://lod.bco-dmo.org/id/dataset-parameter/34039.rdf
Name: station_GEOTRC
Units: dimensionless
Description: GEOTRACES station number; ranges from 1 through 12 for KN199-04 and 1 through 24 for KN204-01. Stations 7 and 9 were skipped on KN204-01. PI-supplied values were identical to those in the intermediate
US GEOTRACES master file. Originally submitted as 'Station', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34040.rdf
Name: depth_GEOTRC_CTD
Units: meters
Description: Observation/sample depth in meters, calculated from CTD pressure. PI-supplied values were identical to those in the
intermediate US GEOTRACES master file. Originally submitted as 'CTD Depth', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34041.rdf
Name: press
Units: decibars
Description: Pressure (dbars) from CTD.
http://lod.bco-dmo.org/id/dataset-parameter/34042.rdf
Name: event_GEOTRC
Units: dimensionless
Description: Unique identifying number for US GEOTRACES sampling events; ranges from 2001 to 2225 for KN199-04 events and from 3001 to 3282 for KN204-01 events. PI-supplied values were identical to those in the intermediate
US GEOTRACES master file. Originally submitted as 'Event number', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34044.rdf
Name: cast_GEOTRC
Units: dimensionless
Description: Cast identifier, numbered consecutively within a station. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Cast', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34045.rdf
Name: sample_GEOTRC
Units: dimensionless
Description: Unique identifying number for US GEOTRACES samples; ranges from 5033 to 6078 for KN199-04 and from 6112 to 8148 for KN204-01. PI-supplied values were identical to those in the
intermediate US GEOTRACES master file. Originally submitted as 'GEOTRACES ID', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34047.rdf
Name: sample_bottle_GEOTRC
Units: dimensionless
Description: Unique identification numbers given to samples taken from bottles; rangies from 1 to 24; often used synonymously with bottle number. PI-supplied values were identical to those in the
intermediate US GEOTRACES master file. Originally submitted as 'Sample #', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34048.rdf
Name: bottle_GEOTRC
Units: dimensionless
Description: Alphanumeric characters identifying bottle type (e.g., NIS representing Niskin and GF representing GOFLO) and position on a CTD rosette. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Bottle number', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.
http://lod.bco-dmo.org/id/dataset-parameter/34049.rdf
Name: month_gmt
Units: unitless
Description: 2-digit month of year (GMT). in the format mm (01 to 12)
http://lod.bco-dmo.org/id/dataset-parameter/34050.rdf
Name: day_gmt
Units: unitless
Description: 2-digit day of month (GMT). in the format dd (01 to 31)
http://lod.bco-dmo.org/id/dataset-parameter/34051.rdf
Name: year
Units: unitless
Description: 4-digit year. in the format YYYY
http://lod.bco-dmo.org/id/dataset-parameter/34052.rdf
Name: time_gmt
Units: unitless
Description: Time (GMT) in hours and minutes when the event occurred; 24-hour clock. in the format HHMM
http://lod.bco-dmo.org/id/dataset-parameter/34053.rdf
Name: lat
Units: decimal degrees
Description: Latitude in decimal degrees. North = Positive.
http://lod.bco-dmo.org/id/dataset-parameter/34054.rdf
Name: lon
Units: decimal degrees
Description: Longitude in decimal degrees. West = Negative.
http://lod.bco-dmo.org/id/dataset-parameter/34055.rdf
Name: d15N_NO3
Units: per mil
Description: Nitrate delta 15N, reported in units of permil vs. atmospheric N2.
http://lod.bco-dmo.org/id/dataset-parameter/34056.rdf
Name: d15N_NO3_sd
Units: per mil
Description: Standard deviation of d15N_NO3.
http://lod.bco-dmo.org/id/dataset-parameter/34057.rdf
Name: n
Units: dimensionless
Description: n; number of observations/measurements.
http://lod.bco-dmo.org/id/dataset-parameter/34058.rdf
Name: flag_low_area
Units: dimensionless
Description: Samples that contained major ion peak areas (m/z 44) less than 1 volt-second are flagged at "low area". The flagged samples should be treated with caution.
http://lod.bco-dmo.org/id/dataset-parameter/34059.rdf
Name: flag_low_conc
Units: dimensionless
Description: Samples analyzed with concentrations below 0.3 uM are were flagged as "low concentration". The flagged samples should be treated with caution.
http://lod.bco-dmo.org/id/dataset-parameter/34060.rdf
Name: ISO_DateTime_UTC
Units: unitless
Description: Date/Time (UTC) of the cast formatted to the ISO8601 standard. T indicates start of time string; Z indicates UTC. in the format YYYY-mm-ddTHH:MM:SS.ssZ
http://lod.bco-dmo.org/id/dataset-parameter/34061.rdf
Name: BTL_ISO_DateTime_UTC
Units: yyyy-MM-dd'T'HH:mm:ss.SS'Z'
Description: Date and time (UTC) that the bottle was fired, in ISO compliant format. Values were added from the intermediate US GEOTRACES master file (see Processing Description). This standard is based on
ISO 8601:2004(E) and takes on the following form: 2009-08-30T14:05:00[.xx]Z (UTC time)
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
64464
https://darchive.mblwhoilibrary.org/bitstream/1912/25597/1/dataset-3913_gt10-11-delta-15n-no3__v1.tsv
download
https://doi.org/10.26008/1912/bco-dmo.3913.1
download
onLine
dataset
<p><strong>Sampling:</strong><br />
Full depth and super station samples were collected from the ship's rosette. Samples were filtered through 0.8/0.45 um acropak500 filter cartridges into triple-rinsed 60 mL HDPE bottles. Demi station samples were collected from the GEOTRACES Go-Flo rosette. Samples were filtered through 0.2 um acropak capsule filters into triple-rinsed 60 mL HDPE bottles. Each sample was collected in triplicate. Samples were frozen at -20 C immediately and stored frozen until analysis.</p>
<p><strong>Analysis:</strong><br />
Samples were analyzed for nitrate d15N and d18O using the denitrifier method (Sigman et al., 2001; Casciotti, et al., 2001, with technical updates described by McIlvin and Casciotti, 2011). Nitrate isotope reference materials USGS32, USGS34, and USGS35 were used to calibrate d18O and USGS32 and USGS34 to calibrate d15N. Each sample was analyzed 2-6 times. Mean and standard deviations are reported for each sample. All samples were analyzed on a DeltaPLUS XP isotope ratio mass spectrometer, with custom-built inlet described in McIlvin and Casciotti, 2011.</p>
<p>Where possible (concentrations exceeded 2 uM), samples and standards were analyzed in 20 nanomole aliquots. When NO3- concentrations were below 2 uM, samples were injected in maximum volume (10 mL) and calibrated using interpolations between standard curves of 5 and 20 nano moles NO3-. Some samples contained nitrate concentrations lower than the typical analytical window (300 nM NO3-), but were analyzed nonetheless. Samples analyzed with concentrations below 0.3 uM are were flagged as "low concentration". These samples contained a subset with major ion peak areas (m/z 44) less than 1 volt-second, which are flagged at "low area". Two of these samples are flagged as having elevated d18O-NO3 values relative to their d15N-NO3 values. The flagged samples should be treated with caution.</p>
<p>This version (16 March 2013) has not been thoroughly intercalibrated with data from the Sigman Lab. Currently, there exists no detachable d15N offset between the datasets. However, Casciotti d18O data are approximately 0.6 permil higher than Sigman d18O data.</p>
Specified by the Principal Investigator(s)
<p><strong>Processing:</strong><br />
Raw data were calibrated to USGS standards analyzed 6x with each batch of samples. The measured values of these reference materials were used to calibrated the measured d15N and d18O values to the atmospheric N2 and VSMOW reference scales (McIlvin and Casciotti, 2011).</p>
<p><strong>References:</strong><br />
McIlvin, M., and K. L. Casciotti. 2011. Technical updates to the bacterial method for nitrate isotopic analyses. Analytical Chemistry 83: 1850-1856.</p>
<p><strong>BCO-DMO Processing Notes:</strong><br />
- Modified parameter names to conform with BCO-DMO naming conventions.<br />
- Separated original date field into month, day, and year.<br />
- Replaced asterisks in the flag columns with the text "low_area" or "low_concentration". "no_flag" added for unflagged data.<br />
- Replaced blanks with 'nd' to indicate 'no data'.<br />
- Corrected event numbers of KN199-04 station 6 cast 1, station 7 cast 6, and station 9 cast 3 to be consistent with those in the event log and bottle files, per approval by PI. (29-April-2013)</p>
<p><strong>Additional GEOTRACES Processing:</strong><br />
After the data were submitted to the International Data Management Office, BODC, the office noticed that important identifying information was missing in many datasets. With the agreement of BODC and the US GEOTRACES lead PIs, BCO-DMO added standard US GEOTRACES information, such as the US GEOTRACES event number, to each submitted dataset lacking this information. To accomplish this, BCO-DMO compiled a 'master' dataset composed of the following parameters: station_GEOTRC, cast_GEOTRC (bottle and pump data only), event_GEOTRC, sample_GEOTRC, sample_bottle_GEOTRC (bottle data only), bottle_GEOTRC (bottle data only), depth_GEOTRC_CTD (bottle data only), depth_GEOTRC_CTD_rounded (bottle data only), BTL_ISO_DateTime_UTC (bottle data only), and GeoFish_id (GeoFish data only). This added information will facilitate subsequent analysis and inter comparison of the datasets.<br />
<br />
Bottle parameters in the master file were taken from the GT-C_Bottle_GT10, GT-C_Bottle_GT11, ODF_Bottle_GT10, and ODF_Bottle_GT11 datasets. Non-bottle parameters, including those from GeoFish tows, Aerosol sampling, and McLane Pumps, were taken from the Event_Log_GT10 and Event_Log_GT11 datasets. McLane pump cast numbers missing in event logs were taken from the Particulate Th-234 dataset submitted by Ken Buesseler.<br />
<br />
A standardized BCO-DMO method (called "join") was then used to merge the missing parameters to each US GEOTRACES dataset, most often by matching on sample_GEOTRC or on some unique combination of other parameters.<br />
<br />
If the master parameters were included in the original data file and the values did not differ from the master file, the original data columns were retained and the names of the parameters were changed from the PI-submitted names to the standardized master names. If there were differences between the PI-supplied parameter values and those in the master file, both columns were retained. If the original data submission included all of the master parameters, no additional columns were added, but parameter names were modified to match the naming conventions of the master file.<br />
<br />
See the dataset parameters documentation for a description of which parameters were supplied by the PI and which were added via the join method.</p>
Specified by the Principal Investigator(s)
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
GO-FLO Bottle
GO-FLO Bottle
PI Supplied Instrument Name: GO-FLO Bottle PI Supplied Instrument Description:Demi station samples were collected from the GEOTRACES GO-FLO rosette. The U.S. GEOTRACES sampling system consisted of 24 Teflon-coated GO-FLO bottles. 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/
Niskin bottle
Niskin bottle
PI Supplied Instrument Name: Niskin bottle Instrument Name: Niskin bottle Instrument Short Name:Niskin bottle Instrument Description: A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/
Isotope-ratio Mass Spectrometer
Isotope-ratio Mass Spectrometer
PI Supplied Instrument Name: Isotope-ratio Mass Spectrometer PI Supplied Instrument Description:All samples were analyzed on a DeltaPLUS XP isotope ratio mass spectrometer, with custom-built inlet described in McIlvin and Casciotti, 2011. Instrument Name: Isotope-ratio Mass Spectrometer Instrument Short Name:IR Mass Spec; IRMS Instrument Description: The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/
Cruise: KN199-04
KN199-04
R/V Knorr
Community Standard Description
International Council for the Exploration of the Sea
R/V Knorr
vessel
KN199-04
William J. Jenkins
Woods Hole Oceanographic Institution
http://bcodata.whoi.edu/US_GEOTRACES/AtlanticSection/Cruise_Report_for_Knorr_199_Final_v3.pdf
Report describing KN199-04
Cruise: KN204-01
KN204-01
R/V Knorr
Community Standard Description
International Council for the Exploration of the Sea
R/V Knorr
vessel
KN204-01
Edward A. Boyle
Massachusetts Institute of Technology
http://bcodata.whoi.edu/US_GEOTRACES/AtlanticSection/STS_Prelim_GT11_Doc.pdf
Report describing KN204-01
R/V Knorr
Community Standard Description
International Council for the Exploration of the Sea
R/V Knorr
vessel