CFC, and noble gas measurements during POLARSTERN cruise PS82 (ANT-XXIX/9)


The tracer data set was carefully checked for accurate measurements and outliers. According to the WOCE standards the following flags were applied to each measurement: ? = flag 3 = doubtful; / = flag 4 = bad, # = flag 6 = mean of replicates.Noble gases (3He, 4He, 20Ne): We took 540 water samples for stable noble gas isotopes (3He, 4He, Ne) in copper tubes from 68 stations. In the IUP Bremen noble gas lab the samples were processed in a first step with a UHV (ultra high vacuum) gas extraction system. The required vacuum conditions are achieved by a rotary pump and an oil diffusion pump. To maintain contamination-free samples, the extraction system is checked for leaks on each sample separately. Sample gases are transferred via water vapour into a glass ampoule kept at liquid nitrogen temperature. Quality checks of this sample preparation line are done on a routine basis. This includes special vacuum checks and preparing accurately defined samples for internal control measurement. For analysis of the noble gas isotopes the glass ampoules are connected to a fully automated UHV mass spectrometric system equipped with a two stage cryo system. Every 2 to 4 samples the system is calibrated with atmospheric air standards (reproducibility <0.2%). Also measurement of line blanks and linearity are done. The performance of the Bremen facility is described in Sültenfuß et al. (2009, doi:10.1080/10256010902871929). Error estimate for absolute He and Ne concentrations and the d3He: D(4He) < 1.0 %D(Ne) < 1.0 %D(d3He) < 0.5 % Chlorofluorocarbons (CFC-11, CFC-12): For the transient tracers (chlorofluorocarbons, CFC-11, CFC-12), we took 1080 samples on 94 stations. The Chlorofluorocarbon (CFC-11 and CFC-12) water samples from the CTD-bottle-system are stored in glass ampoules without contact to the atmosphere during the taping. Immediately after sampling the ampoules are flame sealed after a CFC free headspace of pure nitrogen had been applied. The loss of CFCs into the headspace is considered by a careful equilibration between liquid and gas phase under controlled conditions before the sealed ampoules are opened and a precise measurement of the volume of the headspace. The determination of CFC concentrations in the IUP Bremen gas chromatography lab is accomplished by purge and trap sample pre-treatment followed by gas chromatographic (GC) separation on a capillary column and electron capture detection (ECD). The system is calibrated by analyzing several different volumes of a known standard gas. CFC concentrations are calibrated on SIO98 scale (Prinn et al., 2000, doi:10.1029/2000JD900141). A more detailed description of the measurement system is given by Bulsiewicz et at. (1998, doi:10.1029/98JC00140). Concentrations of CFC-11 and CFC-12 reported on SIO 98 scale (Prinn et al., 2000, doi:10.1029/2000JD900141). Overall accuracy, including that off the calibration scale is estimated to be 2.5% for CFC-11 and 1.5% for CFC-12. The accuracy accounts for uncertainties of calibrated sample volume, calibration curve, extraction efficiency, standard and working gas, water blank, etc. Acknowledgment: Sampling on board and measurement of CFCs and noble gases at the IUP Bremen was funded by the Deutsche Forschungsgemeinschaft within the SPP 1158 "Antarktisforschung", grant HU 1544/4-1. We thank Rainer Knust and the scientific party to participate in the ANT XXIX/9 expedition and for the excellent assistance and cooperation on board. We thank also master and crew of RV Polarstern.

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Creator Huhn, Oliver ORCID logo; Rhein, Monika ORCID logo; Schröder, Michael; Bulsiewicz, Klaus; Sültenfuß, Jürgen ORCID logo
Publisher PANGAEA
Publication Year 2017
Funding Reference German Research Foundation Crossref Funder ID 5472008 Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas
Rights Licensing unknown: Please contact principal investigator/authors to gain access and request licensing terms; Data access is restricted (moratorium, sensitive data, license constraints)
OpenAccess false
Resource Type Dataset
Format text/tab-separated-values
Size 4082 data points
Discipline Earth System Research
Spatial Coverage (-38.954W, -77.920S, -25.743E, -73.465N); Weddell Sea
Temporal Coverage Begin 2014-01-02T14:51:00Z
Temporal Coverage End 2014-02-12T23:41:00Z