Transient tracers (CFC-12 and SF6), noble gases (He and Ne isotopes), and Tritium measurements from POLARSTERN cruise PS122 (MOSAiC, 2019-2020)

• Main Authors: Huhn, Oliver, Heuzé, Céline, Walter, Maren, Mertens, Christian, Bulsiewicz, Klaus, Sültenfuß, Jürgen
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: AC3; Arctic; Arctic Amplification; Arctic Ocean; Bottle number; CFC12; CTD/Rosette; CTD-RO; Date/Time of event; DEPTH; water; Elevation of event; Event label; Freon-12 (dichlorodifluoromethane); Gas chromatographic (GC) separation on a capillary column; electron capture detection (ECD); Helium; Helium-4; Identification; Latitude of event; Longitude of event; MOSAiC; MOSAIC_PO; MOSAiC20192020; MOSAiC expedition; Multidisciplinary drifting Observatory for the Study of Arctic Climate; Neon; Polarstern; Pressure; PS122/1; PS122/1_10-14; PS122/1_10-44; PS122/1_10-60; PS122/1_6-81; PS122/1_7-49; PS122/1_7-80; PS122/1_8-46; PS122/1_8-71; PS122/1_9-50; PS122/2; PS122/2_16-21; PS122/2_16-34; PS122/2_17-41; PS122/2_18-34; PS122/2_19-56; PS122/2_20-46; PS122/2_21-65; PS122/2_22-47; Laptev Sea; Fram Strait; laptev; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.961729; https://doi.org/10.1594/PANGAEA.961729

We present a data set of oceanic trace gases collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, PS122) expedition, during which the R/V Polarstern drifted along with the Arctic sea ice from the Laptev Sea to Fram Strait, from October 2019 to September 2020. During the expedition, trace gases from anthropogenic origin chlorofluorocarbon 12 (CFC-12), sulfur hexafluoride (SF6), and tritium, along with noble gases helium and neon and their isotopes were collected at a weekly or higher temporal resolution throughout the entire water column and occasionally in the snow, from the ship and from the ice. This trace gases data set can be used for process studies and water mass tracing throughout the Arctic in subsequent analysis. Transient tracers (CFC-12, SF6) The CFC-12 and SF6 water samples from the CTD-bottle systems were stored in ~220 ml glass ampoules by avoiding contact to the atmosphere during the tapping by a dedicated tubing and rinsing procedure. After sampling, the ampoules are flame sealed after a headspace of pure nitrogen had been applied. The determination of CFC-12 and SF6 concentrations in the IUP Bremen gas chromatography lab is accomplished by purge and trap (cryogenic trapping at -65°C) sample pre-treatment of a precise water volume of 140 ml followed by gas chromatographic separation on a capillary column and electron capture detection (ECD). After thermal desorption the released gases are separated on a pre-column of type Aluminia Bond/CFC, 0.54 mm ID x 3m, and a main column of type Aluminia BOND/CFC, 0.54 mm ID x 30 m. SF6 and CFC-12 are then detected on a micro-ECD. The analytical system is calibrated frequently by analyzing different volumes of known standard gas concentrations. The loss of CFCs and SF6 into the headspace is considered by equilibration between liquid and gas phase under controlled conditions before the sealed ampoules are opened and the volume of the headspace was precisely measured. A more detailed description of the measurement ...