http://lod.bco-dmo.org/id/dataset/684872
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
2017-03-20
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Export fluxes of Th, POC, PON and bSi calcuated using sediment traps and thorium budget from samples collected on R/V Yellowfin cruises to the San Pedro Ocean Time-series (SPOT) in 2013 and 2014
2017-03-08
publication
2017-03-08
revision
BCO-DMO Linked Data URI
2017-03-08
creation
http://lod.bco-dmo.org/id/dataset/684872
William Haskell
University of California-Santa Barbara
principalInvestigator
Douglas E. Hammond
University of Southern California
principalInvestigator
Maria Prokopenko
Pomona College
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: Haskell, W., Prokopenko, M., Hammond, D. E. (2017) Export fluxes of Th, POC, PON and bSi calcuated using sediment traps and thorium budget from samples collected on R/V Yellowfin cruises to the San Pedro Ocean Time-series (SPOT) in 2013 and 2014. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 08 March 2017) Version Date 2017-03-08 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/684872 [access date]
Export fluxes of Th, POC, PON and bSi calcuated using sediment traps and thorium budget Dataset Description: <p>Export fluxes of Th, POC, PON and bSi calcuated using sediment traps and thorium budget. Measurements were made at the San Pedro Ocean Time-series (SPOT) station (33 33'N, 118 24'W). Data are also published in Table 4 in the following publication:<br />
Haskell, W. Z., et al. 2016. An organic carbon budget for coastal Southern California determined by estimates of vertical nutrient flux, net community production and export. Deep-Sea Research I, 116, 49-76. doi:<a href="http://dx.doi.org/10.1016/j.dsr.2016.07.003" target="_blank">10.1016/j.dsr.2016.07.003</a></p> Methods and Sampling: <p><strong>See complete methodology in Haskell et al. (2016). In summary</strong>:<br />
This study is part of an effort aimed at characterizing the biological response to upwelling at SPOT on 21 cruises between January 2013 and June 2014; the Upwelling Regime In-Situ Ecosystem Efficiency (Up.R.I.S.E.E.) study.</p>
<p><strong>Sediment traps</strong>:&nbsp;During 13 of the 22 cruises, one string of surface-tethered drifting sediment traps containing two Particle-Interceptor-Traps (PITs) was deployed at 100 m and 200 m. A 50 m section of 1-inch thick bungee cord was inserted to dampen the movement caused by waves. A series of five surface buoys were attached to the line and to a mast buoy, which held a strobe light, radio transmitter, radar reflector and Pacific Gyre GPS satellite transmitter. Each trap had a total surface area of 0.0851 m2. All traps had 12 collection tubes with an aspect ratio of 6.4 and had 1 cm x 1 cm baffles fitted into the top opening of the tubes. Funnels with centrifuge tubes were attached into the base of each trap tube. The centrifuge tube (50 ML) contained a brine solution of NaCl (in excess of sea water by 5 ppt) prepared from filtered seawater that was poisoned with 3% formaldehyde and buffered with disodium tetraborate. Deployments averaged 25 h, and were typically deployed near noon. After recovery, each trap was covered and allowed to settle for at least 1 h before the water overlying the centrifuge tubes was siphoned off and the tubes removed from the bottom of each trap tube and capped. For all trap deployments, material from each trap were then filtered onto Whatman Nuclepore polycarbonate membrane (0.4 um) filters and left to dry at room temperature for 2 days. Each filter was folded and put in a counting tube, and placed in a gamma detector (same as Th analysis) to measure thorium and beryllium activities. After counting, the filters were removed from the tubes, the trap material scraped off and homogenized into powder with a mortar and pestle, then divided into three splits. One&nbsp;split was placed in silver foil, acidified with HCl fumes to drive off the inorganic C, and then pelletized. One split was placed in tin foil without acidification. Both splits were sent to the UC Davis Stable Isotope Facility (SIF) for C and N elemental analysis via an isotope ratio mass spectrometer.&nbsp;A third split was transferred to a centrifuge tube for digestion in Na2CO3 to measure biogenic silica (SiO2) using colorimetric analysis at USC. The results of each analysis were then scaled up by weight percent to the initial mass weight of the entire trap catch. Uncertainty in surface-tethered sediment trap fluxes are reported here as +/- 50%.</p>
<p><strong>Sediment trap-based export production</strong>:&nbsp;Rates of carbon and nitrogen export in sinking particles from the<br />
surface ocean were calculated during 13 surface-tethered sediment trap deployments.&nbsp;Biogenic Si (bSi) was measured in trap material during 9 of the 13 trap deployments.</p>
<p><strong>Thorium-234</strong>:&nbsp;Vertical profiles from the surface to 200 m were collected for thorium via Niskin/CTD on every cruise. Ten liters were collected at eight depths, chosen based on the fluorescence profile observed during the CTD's descent. A 229Th spike of known activity was added to the samples as they were being transferred from Niskins into 10 L or 20 L polycarbonate carboys (to an activity ~0.9 dpm/L) and allowed to equilibrate for at least 24 h.&nbsp;The recovery yield of 229Th in each sample was used in all calculations of 234Th to correct for methodological efficiency. The samples were coprecipitated with MnO2 using the technique originally developed by Rutgers van der Loeff and Moore (1999) and detailed in Haskell et al. (2013). Samples were filtered onto a 0.45 um Pall Supor Membrane filter (142 mm).&nbsp;The filters were dried at room temperature, placed in a plastic test tube, and placed in an Ortec low background gamma detector (intrinsic germanium, well-type, 150cc active volume).</p>
<p><strong>234Th/238U disequilibrium</strong>: In order to constrain particle export, we calculated 234Th export from the upper 100 m, by integrating the 234Th/238U disequilibrium. The disequilibrium at each station was calculated using trapezoidal integration of the difference between 238U activity and 234Th activity from the surface to the depth at which the sediment traps were deployed. We use the approach outlined in Haskell et al. (2015b) when calculating the particle export of 234Th (PTh), assuming steady-state. The export flux of particulate organic carbon (POC) out of the zone of 234Th deficiency can be estimated from PTh if the ratio of POC:234Th in sinking particles is established. In this study, POC and 234Th were measured on material caught in sediment traps set at 100 m and 200 m. This ratio is then used in the following equation to estimate POC export:</p>
<p>POCflux = PTh * (POC: 234Th)</p>
<p>For 7 of the 20 sampling periods, there were not any accompanying sediment traps to measure the ratio. For these, we used the most recent ratio measured in the calculation of POC flux, except for the first cruise (SP42) where we used the seasonal average since it occurred a month prior to the most recent trap deployment.</p>
<p><strong>Thorium-based export:&nbsp;</strong>The 234Th: 238U disequilibrium approach for estimating POC export was used for every cruise except Up-14 and Up-16, providing insight into particle export fluxes between sediment trap deployments. Generally, export estimates calculated using this approach agreed well with those calculated using the sediment trap approach, although in most cases, they were larger in magnitude.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1260296 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1260296
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1260692 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1260692
completed
William Haskell
University of California-Santa Barbara
Marine Science Institute, University of California
Santa Barbara
CA
93106
USA
haskell@ucsb.edu
pointOfContact
Douglas E. Hammond
University of Southern California
310-490-7896
3651 Trousdale Pkwy Earth Sciences ZHS117
Los Angeles
CA
90089-0740
USA
dhammond@usc.edu
pointOfContact
Maria Prokopenko
Pomona College
323-630-4068
185 E Sixth St
Claremont
CA
91711-4434
US
Maria.Prokopenko@pomona.edu
pointOfContact
asNeeded
Dataset Version: 08 March 2017
Unknown
site
lat
lon
cruise_id
date
year
month
day
yrday
depth
mass_flux_sed
Corg_to_Th_sed
Be_to_Th_sed
Corg_to_N_sed
bSi_to_Th_sed
Th_flux_sed
Th_flux_sed_sd
Corg_flux_sed
Corg_flux_sed_sd
N_flux_sed
N_flux_sed_sd
bSi_flux_sed
bSi_flux_sed_sd
Th_flux_Th
Th_flux_Th_sd
Corg_flux_Th
Corg_flux_Th_sd
N_flux_Th
N_flux_Th_sd
bSi_flux_Th
bSi_flux_Th_sd
Mean_Corg_flux
Mean_Corg_flux_sd
Seabird CTD
Isotope-ratio mass spectrometer
Niskin bottle
surface-tethered drifting sediment traps
Particle-Interceptor-Traps (PITs)
theme
None, User defined
site
latitude
longitude
Cruise identfier
date
year
month of year
day of month
year day (Day of Year, or day of year and decimal time)
depth
No BCO-DMO term
featureType
BCO-DMO Standard Parameters
CTD Sea-Bird
Isotope-ratio Mass Spectrometer
Niskin bottle
Sediment Trap
Sediment Trap - Particle Interceptor
instrument
BCO-DMO Standard Instruments
UpRISEE_SPOT_13-14
service
Deployment Activity
San Pedro Basin
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: Use of Triple Oxygen Isotopes and O2/Ar to constrain Net/Gross Oxygen Production during upwelling and non-upwelling periods in a Coastal Setting
https://osprey.bco-dmo.org/project/675313
Collaborative Research: Use of Triple Oxygen Isotopes and O2/Ar to constrain Net/Gross Oxygen Production during upwelling and non-upwelling periods in a Coastal Setting
<p>The marine biological pump is one of the primary pathways via which anthropogenic carbon dioxide may be sequestered from the atmosphere and exported to the deep ocean as organic carbon. While the link between nutrient supply and high primary productivity in upwelling regions is well established, factors controlling the organic carbon export efficiency of upwelling ecosystems are not well known. Scientists from the University of Southern California and Pomona College plan to determine the factors that control the rates and magnitudes of two components of biological production, Net Community Production (NCP) and Gross Primary Production (GPP), as well as particulate organic carbon export efficiency, at the San Pedro Ocean Time Series, a coastal site in the California Borderland during periods of minimal and high upwelling velocity over a 2-year span. At this site, past and ongoing observations of hydrography and carbon rain will provide an historical context for interpreting results and mechanisms at work.</p>
<p>Rates of NCP and GPP will be quantified at different upwelling intensity, using dissolved oxygen to argon (O2/Ar) ratios and the oxygen triple isotope composition of dissolved oxygen (O2). The export of organic carbon will be established using 234Th (thorium) profiles in the water column, coupled with floating sediment trap deployments, and the development of a carbon isotope balance for the water column. Upwelling will be characterized using non-steady state budgets for atmospheric 7Be (beryllium) input and its depth-integrated decay, as well as estimating rates based on remote measurements of wind stress curl and budgets for dissolved inorganic carbon and silicon. Application of the O2/Ar ratio and the oxygen triple isotope approach will require depth-integrated profiles of these tracers to evaluate the impact of upwelling on mixed layer inputs and use of non-steady state models during seasonal transitions in upwelling. The comprehensive data set to be obtained should provide insights into the organic carbon export efficiency under variable upwelling regimes and help to relate the satellite-based measurements of chlorophyll to the organic carbon export of these highly productive ecosystems.</p>
<p>Broader Impacts: One graduate and one undergraduate student from the University of Southern California and two undergraduate students from Pomona College would be supported and trained as part of this project.</p>
UpRISEE O2 upwelling
largerWorkCitation
project
eng; USA
oceans
San Pedro Basin
-118.4
-118.4
33.55
33.55
2013-01-16
2014-06-19
Northeast Pacific Ocean
0
BCO-DMO catalogue of parameters from Export fluxes of Th, POC, PON and bSi calcuated using sediment traps and thorium budget from samples collected on R/V Yellowfin cruises to the San Pedro Ocean Time-series (SPOT) in 2013 and 2014
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/684911.rdf
Name: site
Units: unitless
Description: <p>Name of the site</p>
http://lod.bco-dmo.org/id/dataset-parameter/684912.rdf
Name: lat
Units: decimal degrees
Description: <p>Latitude of the site</p>
http://lod.bco-dmo.org/id/dataset-parameter/684913.rdf
Name: lon
Units: decimal degrees
Description: <p>Longitude of the site</p>
http://lod.bco-dmo.org/id/dataset-parameter/684914.rdf
Name: cruise_id
Units: unitless
Description: <p>Cruise identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/684915.rdf
Name: date
Units: unitless
Description: <p>Date of sampling formatted as yyyy-mm-dd</p>
http://lod.bco-dmo.org/id/dataset-parameter/684916.rdf
Name: year
Units: unitless
Description: <p>4-digit year</p>
http://lod.bco-dmo.org/id/dataset-parameter/684917.rdf
Name: month
Units: unitless
Description: <p>2-digit month</p>
http://lod.bco-dmo.org/id/dataset-parameter/684918.rdf
Name: day
Units: unitless
Description: <p>2-digit day</p>
http://lod.bco-dmo.org/id/dataset-parameter/684919.rdf
Name: yrday
Units: unitless
Description: <p>Year day (sequential day of year, eg. Jan 1 = 1)</p>
http://lod.bco-dmo.org/id/dataset-parameter/684920.rdf
Name: depth
Units: meters (m)
Description: <p>Sample depth</p>
http://lod.bco-dmo.org/id/dataset-parameter/684921.rdf
Name: mass_flux_sed
Units: milligrams per square meter per day (mg m-2 d-1)
Description: <p>Sediment trap-based mass flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684922.rdf
Name: Corg_to_Th_sed
Units: micromoles per disintegrations per minute (umol dpm-1)
Description: <p>Ratio of organic carbon to thorium (sediment trap-based)</p>
http://lod.bco-dmo.org/id/dataset-parameter/684923.rdf
Name: Be_to_Th_sed
Units: unitless
Description: <p>Ratio of beryllium to thorium (sediment trap-based)</p>
http://lod.bco-dmo.org/id/dataset-parameter/684924.rdf
Name: Corg_to_N_sed
Units: unitless
Description: <p>Ratio of organic carbon to nitrogen (sediment trap-based)</p>
http://lod.bco-dmo.org/id/dataset-parameter/684925.rdf
Name: bSi_to_Th_sed
Units: micromoles per disintegrations per minute (umol dpm-1)
Description: <p>Ratio of biogenic silica to thorium (sediment trap-based)</p>
http://lod.bco-dmo.org/id/dataset-parameter/684926.rdf
Name: Th_flux_sed
Units: disintegrations per minute per square meter per day (dpm m-2 d-1)
Description: <p>Sediment trap-based thorium flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684927.rdf
Name: Th_flux_sed_sd
Units: disintegrations per minute per square meter per day (dpm m-2 d-1)
Description: <p>Standard deviation of sediment trap-based thorium flux. Uncertainty is reported as 50% for all sediment trap deployments.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684928.rdf
Name: Corg_flux_sed
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Sediment trap-based organic carbon flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684929.rdf
Name: Corg_flux_sed_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of sediment trap-based organic carbon flux. Uncertainty is reported as 50% for all sediment trap deployments.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684930.rdf
Name: N_flux_sed
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Sediment trap-based nitrogen flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684931.rdf
Name: N_flux_sed_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of sediment trap-based nitrogen flux. Uncertainty is reported as 50% for all sediment trap deployments.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684932.rdf
Name: bSi_flux_sed
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Sediment trap-based biogenic silica flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684933.rdf
Name: bSi_flux_sed_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of sediment trap-based biogenic silica flux. Uncertainty is reported as 50% for all sediment trap deployments.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684934.rdf
Name: Th_flux_Th
Units: disintegrations per minute per square meter per day (dpm m-2 d-1)
Description: <p>Thorium flux, using the thorium-based approach</p>
http://lod.bco-dmo.org/id/dataset-parameter/684935.rdf
Name: Th_flux_Th_sd
Units: disintegrations per minute per square meter per day (dpm m-2 d-1)
Description: <p>Standard deviation of thorium flux, using the thorium-based approach. Uncertainty in Th-based approach calculated by propagating uncertainty in upwelling velocity and Th deficiency.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684936.rdf
Name: Corg_flux_Th
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Organic carbon flux, using the thorium-based approach</p>
http://lod.bco-dmo.org/id/dataset-parameter/684937.rdf
Name: Corg_flux_Th_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of organic carbon flux, using the thorium-based approach. Uncertainty in Th-based approach calculated by propagating uncertainty in upwelling velocity and Th deficiency.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684938.rdf
Name: N_flux_Th
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Nitrogen flux, using the thorium-based approach</p>
http://lod.bco-dmo.org/id/dataset-parameter/684939.rdf
Name: N_flux_Th_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of nitrogen flux, using the thorium-based apporach. Uncertainty in Th-based approach calculated by propagating uncertainty in upwelling velocity and Th deficiency.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684940.rdf
Name: bSi_flux_Th
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Biogenic silica flux, using the thorium-based approach</p>
http://lod.bco-dmo.org/id/dataset-parameter/684941.rdf
Name: bSi_flux_Th_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of biogenic silica flux, using the thorium-based approach. Uncertainty in Th-based approach calculated by propagating uncertainty in upwelling velocity and Th deficiency.</p>
http://lod.bco-dmo.org/id/dataset-parameter/684942.rdf
Name: Mean_Corg_flux
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Mean organic carbon flux</p>
http://lod.bco-dmo.org/id/dataset-parameter/684943.rdf
Name: Mean_Corg_flux_sd
Units: millimoles per square meter per day (mmol m-2 d-1)
Description: <p>Standard deviation of mean organic carbon flux. Uncertainty is reported as the same as in Th-based approach.</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
7456
https://datadocs.bco-dmo.org/file/6YYMl65iP0Pjxz/export_fluxes.csv
export_fluxes.csv
Primary data file for dataset ID 684872
download
https://osprey.bco-dmo.org/dataset/684872/data/download
download
onLine
dataset
<p><strong>See complete methodology in Haskell et al. (2016). In summary</strong>:<br />
This study is part of an effort aimed at characterizing the biological response to upwelling at SPOT on 21 cruises between January 2013 and June 2014; the Upwelling Regime In-Situ Ecosystem Efficiency (Up.R.I.S.E.E.) study.</p>
<p><strong>Sediment traps</strong>:&nbsp;During 13 of the 22 cruises, one string of surface-tethered drifting sediment traps containing two Particle-Interceptor-Traps (PITs) was deployed at 100 m and 200 m. A 50 m section of 1-inch thick bungee cord was inserted to dampen the movement caused by waves. A series of five surface buoys were attached to the line and to a mast buoy, which held a strobe light, radio transmitter, radar reflector and Pacific Gyre GPS satellite transmitter. Each trap had a total surface area of 0.0851 m2. All traps had 12 collection tubes with an aspect ratio of 6.4 and had 1 cm x 1 cm baffles fitted into the top opening of the tubes. Funnels with centrifuge tubes were attached into the base of each trap tube. The centrifuge tube (50 ML) contained a brine solution of NaCl (in excess of sea water by 5 ppt) prepared from filtered seawater that was poisoned with 3% formaldehyde and buffered with disodium tetraborate. Deployments averaged 25 h, and were typically deployed near noon. After recovery, each trap was covered and allowed to settle for at least 1 h before the water overlying the centrifuge tubes was siphoned off and the tubes removed from the bottom of each trap tube and capped. For all trap deployments, material from each trap were then filtered onto Whatman Nuclepore polycarbonate membrane (0.4 um) filters and left to dry at room temperature for 2 days. Each filter was folded and put in a counting tube, and placed in a gamma detector (same as Th analysis) to measure thorium and beryllium activities. After counting, the filters were removed from the tubes, the trap material scraped off and homogenized into powder with a mortar and pestle, then divided into three splits. One&nbsp;split was placed in silver foil, acidified with HCl fumes to drive off the inorganic C, and then pelletized. One split was placed in tin foil without acidification. Both splits were sent to the UC Davis Stable Isotope Facility (SIF) for C and N elemental analysis via an isotope ratio mass spectrometer.&nbsp;A third split was transferred to a centrifuge tube for digestion in Na2CO3 to measure biogenic silica (SiO2) using colorimetric analysis at USC. The results of each analysis were then scaled up by weight percent to the initial mass weight of the entire trap catch. Uncertainty in surface-tethered sediment trap fluxes are reported here as +/- 50%.</p>
<p><strong>Sediment trap-based export production</strong>:&nbsp;Rates of carbon and nitrogen export in sinking particles from the<br />
surface ocean were calculated during 13 surface-tethered sediment trap deployments.&nbsp;Biogenic Si (bSi) was measured in trap material during 9 of the 13 trap deployments.</p>
<p><strong>Thorium-234</strong>:&nbsp;Vertical profiles from the surface to 200 m were collected for thorium via Niskin/CTD on every cruise. Ten liters were collected at eight depths, chosen based on the fluorescence profile observed during the CTD's descent. A 229Th spike of known activity was added to the samples as they were being transferred from Niskins into 10 L or 20 L polycarbonate carboys (to an activity ~0.9 dpm/L) and allowed to equilibrate for at least 24 h.&nbsp;The recovery yield of 229Th in each sample was used in all calculations of 234Th to correct for methodological efficiency. The samples were coprecipitated with MnO2 using the technique originally developed by Rutgers van der Loeff and Moore (1999) and detailed in Haskell et al. (2013). Samples were filtered onto a 0.45 um Pall Supor Membrane filter (142 mm).&nbsp;The filters were dried at room temperature, placed in a plastic test tube, and placed in an Ortec low background gamma detector (intrinsic germanium, well-type, 150cc active volume).</p>
<p><strong>234Th/238U disequilibrium</strong>: In order to constrain particle export, we calculated 234Th export from the upper 100 m, by integrating the 234Th/238U disequilibrium. The disequilibrium at each station was calculated using trapezoidal integration of the difference between 238U activity and 234Th activity from the surface to the depth at which the sediment traps were deployed. We use the approach outlined in Haskell et al. (2015b) when calculating the particle export of 234Th (PTh), assuming steady-state. The export flux of particulate organic carbon (POC) out of the zone of 234Th deficiency can be estimated from PTh if the ratio of POC:234Th in sinking particles is established. In this study, POC and 234Th were measured on material caught in sediment traps set at 100 m and 200 m. This ratio is then used in the following equation to estimate POC export:</p>
<p>POCflux = PTh * (POC: 234Th)</p>
<p>For 7 of the 20 sampling periods, there were not any accompanying sediment traps to measure the ratio. For these, we used the most recent ratio measured in the calculation of POC flux, except for the first cruise (SP42) where we used the seasonal average since it occurred a month prior to the most recent trap deployment.</p>
<p><strong>Thorium-based export:&nbsp;</strong>The 234Th: 238U disequilibrium approach for estimating POC export was used for every cruise except Up-14 and Up-16, providing insight into particle export fluxes between sediment trap deployments. Generally, export estimates calculated using this approach agreed well with those calculated using the sediment trap approach, although in most cases, they were larger in magnitude.</p>
Specified by the Principal Investigator(s)
<p>BCO-DMO Processing:<br />
-modified parameter names to conform with BCO-DMO naming conventions;<br />
-formatted dates to yyyy-mm-dd;<br />
-replaced "-" and blanks (missing data) with "nd";<br />
-added site name, lat, and lon from information on metadata form.</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
Seabird CTD
Seabird CTD
PI Supplied Instrument Name: Seabird CTD PI Supplied Instrument Description:Vertical profiles from the surface to 200 m were collected for thorium via Niskin/CTD on every cruise. Instrument Name: CTD Sea-Bird Instrument Short Name:CTD Sea-Bird Instrument Description: A Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics. This instrument designation is used when specific make and model are not known or when a more specific term is not available in the BCO-DMO vocabulary. Refer to the dataset-specific metadata for more information about the specific CTD used. More information from: http://www.seabird.com/ Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/130/
Isotope-ratio mass spectrometer
Isotope-ratio mass spectrometer
PI Supplied Instrument Name: Isotope-ratio mass spectrometer PI Supplied Instrument Description:Splits were sent to the UC Davis Stable Isotope Facility (SIF) for C and N elemental analysis via an isotope ratio mass spectrometer. 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/
Niskin bottle
Niskin bottle
PI Supplied Instrument Name: Niskin bottle PI Supplied Instrument Description:Vertical profiles from the surface to 200 m were collected for thorium via Niskin/CTD on every cruise. 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/
surface-tethered drifting sediment traps
surface-tethered drifting sediment traps
PI Supplied Instrument Name: surface-tethered drifting sediment traps PI Supplied Instrument Description:During 13 of the 22 cruises, one string of surface-tethered drifting sediment traps containing two Particle-Interceptor-Traps (PITs) was deployed at 100 m and 200 m. Instrument Name: Sediment Trap Instrument Short Name:Sediment Trap Instrument Description: Sediment traps are specially designed containers deployed in the water column for periods of time to collect particles from the water column falling toward the sea floor. In general a sediment trap has a jar at the bottom to collect the sample and a broad funnel-shaped opening at the top with baffles to keep out very large objects and help prevent the funnel from clogging. This designation is used when the specific type of sediment trap was not specified by the contributing investigator. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/33/
Particle-Interceptor-Traps (PITs)
Particle-Interceptor-Traps (PITs)
PI Supplied Instrument Name: Particle-Interceptor-Traps (PITs) PI Supplied Instrument Description:During 13 of the 22 cruises, one string of surface-tethered drifting sediment traps containing two Particle-Interceptor-Traps (PITs) was deployed at 100 m and 200 m. Instrument Name: Sediment Trap - Particle Interceptor Instrument Short Name:Sed Trap - Part Int Instrument Description: A Particle Interceptor Trap is a prototype sediment trap designed in the mid 1990s to segregate 'swimmers' from sinking particulate material sampled from the water column. The prototype trap used 'segregation plates' to deflect and segregate 'swimmers' while a series of funnels collected sinking particles in a chamber (see Dennis A. Hansell and Jan A. Newton. September 1994. Design and Evaluation of a "Swimmer"-Segregating Particle Interceptor Trap, Limnology and Oceanography, Vol. 39, No. 6, pp. 1487-1495). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/33/
Cruise: UpRISEE_SPOT_13-14
UpRISEE_SPOT_13-14
R/V Yellowfin
R/V Yellowfin
vessel
R/V Yellowfin
R/V Yellowfin
vessel