Helium Isotopes and Noble Gas Concentrations collected on the U.S GEOTRACES cruise TN303 (EPZT)
Responsible investigator
Dr William Jenkins
email: wjenkins@whoi.edu
Woods Hole Oceanographic Institution
Department of Marine Chemistry and Geochemistry
Woods Hole
MA 02543
US
Data contributor
Dr William Jenkins
email: wjenkins@whoi.edu
Woods Hole Oceanographic Institution
Department of Marine Chemistry and Geochemistry
Woods Hole
MA 02543
US
Laboratory of analysis
Woods Hole Oceanographic Institution
Dataset brief description
Helium Isotopes and Noble Gas Concentrations from GEOTRACES 2013 Eastern Pacific Zonal Transect
Dataset description
Helium Isotopes and Noble Gas Concentrations from GEOTRACES 2013 Eastern Pacific Zonal Transect
Acquisition description
Sampling methodology
Noble gas and helium isotope samples were acquired by gravity-feeding from NISKIN bottle into lengths of 5/8" OD copper tubing which were cold-welded to form replicate ~45 g, helium-leak-tight samples (Young and Lupton, 1983) and returned for shore-based sample extraction and mass-spectrometric analysis. Gases were quantitatively extracted in a bellows-compression UHV vacuum line and quantitatively transferred to ~30 ml aluminosilicate glass ampoules. The gases were purified and cryogenically separated in an automated mass spectrometer processing line (Stanley et al., 2009). Abundances of the light noble gases (He, Ne, and Ar) were determined by QMS ion-current manometry against atmospheric standards to an accuracy 0.2% or better. For a subset of the samples, the heavy noble gases (Kr and Xe) were analysed in a similar fashion subject to an empirical "matrix effect" correction (Stanley, 2007), and these results are characterized by an uncertainty of order 0.3% and 1% for Kr and Xe concentrations respectively. The remainder of the Kr and Xe measurements were done using an improved isotope dilution ratiometry, with subsequent uncertainties of order 0.2%. The isotope dilution ratiometry involved the use of a mono-isotopic 78-Kr and 124-Xe spike combined with the measurement of two other isotopes (82-Kr, 86-Kr, 129-Xe, and 132-Xe) to correct for isotopic fractionation when comparing to running standards.
References cited
Stanley, R. H. R. (2007). A Determination of Air-Sea Gas Exchange Processes and Upper Ocean Biological Production From Five Noble Gases and Tritiugenic Helium-3. PhD, MIT-WHOI Joint Program in Chemical Oceanography.
Stanley, R. H. R., B. Baschek, D. E. I. Lott and W. J. Jenkins (2009). A new automated method for measuring noble gases and their isotopic ratios in water samples. Geochemistry Geophysics Geosystems 10(5): Q05008, doi:05010.01029/02009GC002429.
Young, C. and J. E. Lupton (1983). An ultratight fluid sampling system using cold-welded copper tubing." EOS Transactions AGU 64: 735.
BODC Data Processing Procedures
The mapping between the originator's channels and BODC parameter codes is detailed in the table below:
| Originator's Parameter | Unit | Description | BODC Parameter code | BODC Unit | Comments |
|---|---|---|---|---|---|
| He_3_D_DELTA_BOTTLE | percent | Enrichment of helium-3 {3He CAS 14762-55-1} in the water body [dissolved plus reactive particulate phase] | DHE3XX01 | percent | - |
| He_3_D_DELTA_BOTTLE_ERR | percent | Enrichment combined uncertainty of helium-3 {3He CAS 14762-55-1} in the water body [dissolved plus reactive particulate phase] | DHE3XXER | percent | - |
| He_D_BOTTLE | nanomoles per kilogram | Concentration of helium {He CAS 7440-59-7} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | HEXCMX01 | nanomoles per kg | - |
| He_D_BOTTLE_ERR | nanomoles per kilogram | Concentration uncertainty of helium {He CAS 7440-59-7} per unit mass of the water body [dissolved plus reactive particulate phase] | HEERMASS | nanomoles per kg | - |
| Ne_D_CONC_BOTTLE | nanomoles per kilogram | Concentration of neon {Ne CAS 7440-01-9} per unit mass of the water body [dissolved plus reactive particulate phase] | NECNMASS | nanomoles per kg | - |
| Ne_D_CONC_BOTTLE_ERR | nanomoles per kilogram | Concentration uncertainty of neon {Ne CAS 7440-01-9} per unit mass of the water body [dissolved plus reactive particulate phase] | NEERMASS | nanomoles per kg | - |
| Ar_D_CONC_BOTTLE | micromoles per kilogram | Concentration of argon {Ar CAS 7440-37-1} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CAR77001 | micromoles per kg | - |
| Ar_D_CONC_BOTTLE_ERR | micromoles per kilogram | Concentration uncertainty of argon {Ar CAS 7440-37-1} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CAR77002 | micromoles per kg | - |
| Kr_D_CONC_BOTTLE | nanomoles per kilogram | Concentration of krypton {Kr CAS 7439-90-9} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CKR77003 | nanomoles per kg | - |
| Kr_D_CONC_BOTTLE_ERR | nanomoles per kilogram | Concentration uncertainty of krypton {Kr CAS 7439-90-9} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CKR77004 | nanomoles per kg | - |
| Xe_D_CONC_BOTTLE | nanomoles per kilogram | Concentration of xenon {Xe CAS 7440-63-3} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CXE77005 | nanomoles per kg | - |
| Xe_D_CONC_BOTTLE_ERR | nanomoles per kilogram | Concentration uncertainty of xenon {Xe CAS 7440-63-3} per unit mass of the water body [dissolved plus reactive particulate phase] by mass spectrometry | CXE77006 | nanomoles per kg | - |
Data Quality Report
None.
