Snow, sea ice, slush, brine and seawater: Oxygen isotopic ratio data from the SIPEX II voyage of the Aurora Australis, 2012

Brief description

During the ice stations, sea ice, brine/slush, snow and under-ice water sampling were collected for oxygen isotopic ratio. Ice cores were collected using a Kovacs 9 cm diameter ice corer. The ice core for oxygen isotopic ratio was cut directly after retrieval with a stainless steel folded saw. The core was cut generally into 10 cm sections (20 cm when ice cores were higher than 200 cm) and put into zip-lock polyethylene bags. Care was taken to use laboratory gloves when collecting the cores. For brine sampling, partial core holes were drilled into the ice (so called sackholes), usually to a depth of 25 cm and 50 cm. At site with flooding, brine collection was not possible, and samples of the surface slush were collected instead. Slush was collected by plastic shovel. Snow samples were also collected. Under-ice water was collected with a Teflon water sampler (GL Science Inc., Japan) 1, 3, 5 m below the bottom of the sea ice. In addition, CTD water sampling was examined at each station. The cores were taken back to the ship, and transferred to the gas tight bag (GL Science Inc., Japan), and then ice was melted at about +4 degrees C in a refrigerator. Melted samples were sub-sampled for each component. The snow samples were treated in the same manner as the sea ice samples for further analysis. Oxygen isotopic ratio was determined with a mass spectrometer (DELTA plus; Finnigan MAT, USA) in Hokkaido University. Oxygen isotopic ratio in per mil (parts per thousand) was defined as the deviation of H2 18O/H2 16O ratio of the measured sample to that of the standard mean ocean water (SMOW). The precision of oxygen isotopic ratio analysis from duplicate determinations is plus or minus 0.02 parts per thousand (Toyota et al., 2007). Data available: excel files containing sampling station name, dates, and oxygen isotopic ratio.