http://lod.bco-dmo.org/id/dataset/811839
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
2020-05-19
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Nutrient and nitrate isotope data from the southern Benguela upwelling system from February to August 2017
2020-05-19
publication
2020-05-19
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2020-05-20
publication
https://doi.org/10.26008/1912/bco-dmo.811839.1
Julie Granger
University of Connecticut
principalInvestigator
Samantha Siedlecki
University of Connecticut
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: Granger, J., Siedlecki, S. (2020) Nutrient and nitrate isotope data from the southern Benguela upwelling system from February to August 2017. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2020-05-19 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.811839.1 [access date]
Nutrient and nitrate isotope data from the southern Benguela upwelling system from February to August 2017 Dataset Description: <p>CTD data:<br />
The temperature and conductivity probes are calibrated annually by the manufacturer while the oxygen sensor was calibrated against discrete seawater samples analyzed for dissolved oxygen concentrations by Winkler titration (Carpenter 1965; Grasshoff et al. 1983).</p>
<p>Nutrients:<br />
Duplicate samples were measured for nitrate+nitrite on different days, and the standard deviation for duplicates was &lt;0.5 µM, with a lower standard deviation for lower concentration samples<br />
Duplicate samples for phosphate and nitrite were measured in duplicate on different days of analysis, yielding a standard deviation for duplicates of ≤0.1 µM.&nbsp;</p>
<p>Nitrate isotopes:<br />
The N and O isotope ratios of nitrate were measured in triplicate in separate batch analyses and standard deviations for both δ15N and δ18O were &lt;0.3‰. Certified nitrate isotope ratio reference materials in nutrient-free seawater were measured in all batch analyses. These included IAEA-NO3-, with δ15N of 4.7 ± 0.2‰ vs. N2 air (Gonfiantini et al. 1995) and and δ18O of 25.6 ± 0.4‰ vs. VSMOW (Böhlke et al. 2003), and USGS-34, with δ15N of -1.8 ± 0.1‰ vs. N2 air and δ18O of -27.9 ± 0.3‰ vs. VSMOW (Böhlke et al. 2003). Nitrate isotstandards in individual runs were diluted in nutrient-free seawater to concentrations similar to those of the samples to account for potential matrix effects on the δ18O measurements (Weigand et al. 2016). Reproducibility was monitored by analysis of an internal seawater nitrate standard from the deep North Atlantic.</p> Methods and Sampling: <p>The methods on how the samples were collected and processed for the attached dataset can be found in the methodology section of Flynn et al. (2019).&nbsp;</p>
<p>Hydrographic measurements were made using a conductivity-temperature-depth (CTD) profiler fitted with a temperature, salinity and oxygen sensor.&nbsp;</p>
<p>Nitrate+nitrite concentrations were measured following published auto-analysis protocols (Diamond 1994; Grasshoff 1976), and nitrite and phosphate concentrations were determined using benchtop colourimetric methods (Strickland and Parsons 1968; Bendschneider and Robinson 1952; Parsons et al. 1984).&nbsp;</p>
<p>Nitrate N and O isotope ratios were measured using the “denitrifier method” (Sigman et al. 2001; Casciotti et al. 2002; McIlvin and Casciotti 2011).</p>
<p>Seawater samples were collected at discrete depths from the surface to the seafloor using a tethered rosette holding twelve 6-L Niskin bottles. At each CTD station, nutrient and nitrate isotope samples were collected filtered (0.22 µm PES membrane syringe filter) throughout the water column in 60 mL HDPE bottles. Each bottle was rinsed three times prior to being filled, and then immediately frozen at -20°C pending analysis. All nutrient samples were analysed within a year from collection, and nitrate isotopes within 18 months of collection.&nbsp;</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1924270 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1924270
completed
Julie Granger
University of Connecticut
860-405-9094
Department of Marine Sciences 1080 Shenecossett Road
Groton
CT
06340
USA
julie.granger@uconn.edu
pointOfContact
Samantha Siedlecki
University of Connecticut
(860)405-9031
1080 Schennecossett Road
Groton
CT
USA
Samantha.siedlecki@uconn.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Cruise
Month
Year
Station_ID
Monitoring_line
Latitude
Longitude
Depth
Temperature
Salinity
Sigma_theta
NO3_NO2
NO3_NO2_Stdev
NO2
NO2_Stdev
PO43
PO43_Stdev
O2
AOU
N15_NO3
N15_stdev
O18_NO3
O18_stdev
CTD profiler
Lachat QuickChem flow injection analysis platform
Delta V Advantage continuous flow isotope ratio mass spectrometer
Thermo Scientific Genesis 30 Visible spectrophotometer
theme
None, User defined
cruise name
month of year
year
station
site description
latitude
longitude
depth
water temperature at measurement depth
salinity
sigma-theta potential density
nitrate plus nitrite
Nitrite
reactive phosphorus (PO4)
dissolved Oxygen
Apparent Oxygen Utilization
d15N_NO3
No BCO-DMO term
d18O_NO3
featureType
BCO-DMO Standard Parameters
CTD - profiler
Flow Injection Analyzer
Isotope-ratio Mass Spectrometer
Spectrophotometer
instrument
BCO-DMO Standard Instruments
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.
Investigation of mechanisms leading to seasonal hypoxia in the Southern Benguela Upwelling System
https://osprey.bco-dmo.org/project/809302
Investigation of mechanisms leading to seasonal hypoxia in the Southern Benguela Upwelling System
<p>NSF Award Abstract:</p>
<p>The Southern Benguela Upwelling System (SBUS) in the eastern Atlantic Ocean ranks among the most fertile region in the world ocean, host to economically important fishing grounds. Unfortunately, waters of the SBUS are subject to events wherein dissolved oxygen is severely depleted, a condition also known as seasonal hypoxia, which have been observed to cause substantial fish kills. To gain a better understanding of the processes triggering severe hypoxic events, the study will combine field observations (analyzing water samples for dissolved nitrate, nitrite, ammonium, soluble reactive phosphorus, and silicic acid, as well as nitrate isotopic ratios to identify the origin and fate of nutrients in upwelling systems) and modeling. This combined approach is a powerful means of identifying the processes that contribute to the development of hypoxia in the SBUS and the mechanisms gleaned from the proposed study are likely to extend beyond the SBUS to other upwelling regions, such as the Northern Benguela, California and Peru Upwelling Systems. For outreach activities, graduate students would create a short film on their research in South Africa. This film, made available on the University of Connecticut and the University of Cape Town websites and YouTube, would serve as a means of communicating the science to broader audiences. Two graduate students would be supported and trained as part of this project. These students would have the opportunity to work with the South African collaborators at the University of Cape Town, Drs. Sarah Fawcett and Jennifer Veitch, involved in the study.</p>
<p>The Southern Benguela Upwelling System (SBUS), off the coasts of South Africa and Namibia, is subject to severe seasonal hypoxia which has been observed to have catastrophic impacts on wildlife, fisheries, and national economies. Researcher from the University of Connecticut posit that the propensity for hypoxic events in this region is linked to the extent of nutrient trapping on the shelf inshore of the hydrographic fronts. This, in turn, influences the intensity of subsequent blooms, and the consequent oxygen demand when this organic material is ultimately decomposed at the shelf bottom. To confirm the role of nutrient cycling in modulating hypoxic event, the scientists will utilize a combination of observations and quantitative simulations. Analyses of dissolved nutrients and nitrate isotope ratios from water samples collected on quarterly monitoring cruises in the SBUS will be used to assess the role of nutrient cycling in modulating hypoxic events. Concurrently, an idealized circulation model of the SBUS will be initiated to test the hypotheses surrounding inshore nutrient trapping and incident hypoxia. Specifically, the focus will be on the potential roles of wind intensity and periodicity, shelf frontal structure, and the alongshore pressure gradient in modulating the burden of recycled nutrients trapped on the shelf and its association with hypoxia. Finally, the ocean circulation and biogeochemistry of the SBUS will be modeled using a realistic hind-cast model forced with realistic atmospheric, tidal, and ocean boundary conditions to make hind-cast simulations of the 3-D circulation and hydrography throughout the domain. This coupled physical-biogeochemical model would be queried to fully investigate the proposed nutrient trapping mechanism and define its role in modulating the intensity of hypoxia inter-annually and from which a prognostic model can be developed.</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>
SBUS Hypoxia
largerWorkCitation
project
eng; USA
oceans
14.1348
18.28933333
-34.5593
-29.3817
2017-02-01
2017-08-31
Southern Benguela Upwelling System
0
BCO-DMO catalogue of parameters from Nutrient and nitrate isotope data from the southern Benguela upwelling system from February to August 2017
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/811859.rdf
Name: Cruise
Units: unitless
Description: <p>name of the cruise</p>
http://lod.bco-dmo.org/id/dataset-parameter/811860.rdf
Name: Month
Units: unitless
Description: <p>Month of observation in text</p>
http://lod.bco-dmo.org/id/dataset-parameter/811861.rdf
Name: Year
Units: unitless
Description: <p>year of observation in yyyy format</p>
http://lod.bco-dmo.org/id/dataset-parameter/811862.rdf
Name: Station_ID
Units: unitless
Description: <p>identifier for the station</p>
http://lod.bco-dmo.org/id/dataset-parameter/811863.rdf
Name: Monitoring_line
Units: unitless
Description: <p>identifier for the mooring line</p>
http://lod.bco-dmo.org/id/dataset-parameter/811864.rdf
Name: Latitude
Units: decimal degrees
Description: <p>latitude with negative values indicating South</p>
http://lod.bco-dmo.org/id/dataset-parameter/811865.rdf
Name: Longitude
Units: decimal degrees
Description: <p>longitude with positive values indicating West</p>
http://lod.bco-dmo.org/id/dataset-parameter/811866.rdf
Name: Depth
Units: meters (m)
Description: <p>water depth of observation</p>
http://lod.bco-dmo.org/id/dataset-parameter/811867.rdf
Name: Temperature
Units: degrees Celsius (C)
Description: <p>Temperature</p>
http://lod.bco-dmo.org/id/dataset-parameter/811868.rdf
Name: Salinity
Units: psu
Description: <p>Salinity</p>
http://lod.bco-dmo.org/id/dataset-parameter/811869.rdf
Name: Sigma_theta
Units: kilograms per meter cubed (kg/m3)
Description: <p>sigma-theta</p>
http://lod.bco-dmo.org/id/dataset-parameter/811870.rdf
Name: NO3_NO2
Units: microMole (uM)
Description: <p>[NO3-+NO2-]</p>
http://lod.bco-dmo.org/id/dataset-parameter/811871.rdf
Name: NO3_NO2_Stdev
Units: micr
Description: <p>standard deviation of [NO3-+NO2-]</p>
http://lod.bco-dmo.org/id/dataset-parameter/811872.rdf
Name: NO2
Units: microMole (uM)
Description: <p>NO2-</p>
http://lod.bco-dmo.org/id/dataset-parameter/811873.rdf
Name: NO2_Stdev
Units: microMole (uM)
Description: <p>standard deviation of NO2-</p>
http://lod.bco-dmo.org/id/dataset-parameter/811874.rdf
Name: PO43
Units: microMole (uM)
Description: <p>PO43-</p>
http://lod.bco-dmo.org/id/dataset-parameter/811875.rdf
Name: PO43_Stdev
Units: microMole (uM)
Description: <p>standard deviation of PO43-</p>
http://lod.bco-dmo.org/id/dataset-parameter/811876.rdf
Name: O2
Units: microMole (uM)
Description: <p>O2</p>
http://lod.bco-dmo.org/id/dataset-parameter/811877.rdf
Name: AOU
Units: microMole (uM)
Description: <p>Apparent Oxygen Utilization (AOU)</p>
http://lod.bco-dmo.org/id/dataset-parameter/811878.rdf
Name: N15_NO3
Units: parts per thousand
Description: <p>15N_NO3</p>
http://lod.bco-dmo.org/id/dataset-parameter/811879.rdf
Name: N15_stdev
Units: parts per thousand
Description: <p>standard deviation of δ15N</p>
http://lod.bco-dmo.org/id/dataset-parameter/811880.rdf
Name: O18_NO3
Units: parts per thousand
Description: <p>18O_NO3</p>
http://lod.bco-dmo.org/id/dataset-parameter/811881.rdf
Name: O18_stdev
Units: parts per thousand
Description: <p>standard deviation of δ18O</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
122152
https://darchive.mblwhoilibrary.org/bitstream/1912/25796/1/dataset-811839_iep-february-and-may-2017__v1.tsv
download
https://doi.org/10.26008/1912/bco-dmo.811839.1
download
onLine
dataset
<p>The methods on how the samples were collected and processed for the attached dataset can be found in the methodology section of Flynn et al. (2019).&nbsp;</p>
<p>Hydrographic measurements were made using a conductivity-temperature-depth (CTD) profiler fitted with a temperature, salinity and oxygen sensor.&nbsp;</p>
<p>Nitrate+nitrite concentrations were measured following published auto-analysis protocols (Diamond 1994; Grasshoff 1976), and nitrite and phosphate concentrations were determined using benchtop colourimetric methods (Strickland and Parsons 1968; Bendschneider and Robinson 1952; Parsons et al. 1984).&nbsp;</p>
<p>Nitrate N and O isotope ratios were measured using the “denitrifier method” (Sigman et al. 2001; Casciotti et al. 2002; McIlvin and Casciotti 2011).</p>
<p>Seawater samples were collected at discrete depths from the surface to the seafloor using a tethered rosette holding twelve 6-L Niskin bottles. At each CTD station, nutrient and nitrate isotope samples were collected filtered (0.22 µm PES membrane syringe filter) throughout the water column in 60 mL HDPE bottles. Each bottle was rinsed three times prior to being filled, and then immediately frozen at -20°C pending analysis. All nutrient samples were analysed within a year from collection, and nitrate isotopes within 18 months of collection.&nbsp;</p>
Specified by the Principal Investigator(s)
<p>BCO-DMO Processing Notes:<br />
-&nbsp;added conventional header with dataset name, PI name, version date<br />
- modified parameter names to conform with BCO-DMO naming conventions<br />
- converted positive latitude values for SHGML005 in May 2017 to negative values as they were incorrect.<br />
- removed extra data row at bottom of Aug sheet.</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
CTD profiler
CTD profiler
PI Supplied Instrument Name: CTD profiler PI Supplied Instrument Description:Hydrographic measurements were made using a conductivity-temperature-depth (CTD) profiler fitted with a temperature, salinity and oxygen sensor. 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/
Lachat QuickChem flow injection analysis platform
Lachat QuickChem flow injection analysis platform
PI Supplied Instrument Name: Lachat QuickChem flow injection analysis platform PI Supplied Instrument Description:Nitrate+nitrite concentrations were measured using a Lachat QuickChem flow injection analysis platform in a configuration with a detection limit of 0.1 µM. Instrument Name: Flow Injection Analyzer Instrument Short Name:FIA Instrument Description: An instrument that performs flow injection analysis. Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream. FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB36/
Delta V Advantage continuous flow isotope ratio mass spectrometer
Delta V Advantage continuous flow isotope ratio mass spectrometer
PI Supplied Instrument Name: Delta V Advantage continuous flow isotope ratio mass spectrometer PI Supplied Instrument Description:The N and O isotope ratios of the N2O gas were analysed using a Delta V Advantage continuous flow isotope ratio mass spectrometer interfaced with an online N2O extraction and purification system. 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/
Thermo Scientific Genesis 30 Visible spectrophotometer
Thermo Scientific Genesis 30 Visible spectrophotometer
PI Supplied Instrument Name: Thermo Scientific Genesis 30 Visible spectrophotometer PI Supplied Instrument Description:Phosphate and nitrite concentrations were measured using a Thermo Scientific Genesis 30 Visible spectrophotometer in a configuration with a detection limit of 0.05 µM. Instrument Name: Spectrophotometer Instrument Short Name:Spectrophotometer Instrument Description: An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/