Chlorofluorocarbons, Noble Gases and Tritium measurements during POLARSTERN cruise ANT-XXII/3 - Filchner-Ronne Ice Shelf


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, * = flag 7 = air corrected.Methods Noble gases (3He, 4He, 20Ne) The water samples for helium isotopes and neon from the CTD-bottle-system are tapped in copper tubes, preventing air contamination and bubbles during the filling of the tubes and squeezed at both ends to keep them gas tight during transportation and storage. In the IUP Bremen noble gas lab the samples are 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 vapor 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 noble gases concentrations: D(4He) ± 0.44 % D(Ne) ± 0.40 % D(d3He) ± 0.25 % Chlorofluorocarbons (CFC-11, CFC-12) 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 tapping. 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).Error estimate for CFC-11 and CFC-12 concentrations: CFC-11 ± 7 % CFC-12 ± 3 % Noble gas and CFC data were used e.g. in Huhn et al., 2008 (doi:10.1016/j.dsr2.2007.12.015).

Related Identifier
Metadata Access
Creator Roether, Wolfgang; Huhn, Oliver 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 Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 1640 data points
Discipline Earth System Research
Spatial Coverage (-60.847W, -77.142S, -31.003E, -73.008N)
Temporal Coverage Begin 1995-01-25T09:07:00Z
Temporal Coverage End 1995-03-01T11:20:00Z