alpha- and gamma-Hexachlorocyclohexane concentrations in brine, bulk sea-ice, water and air during a CCGS Amundsen cruise to the Canadian western Arctic, supplement to: Pućko, Monika; Stern, Gary A; Macdonald, Robie W; Barber, David G (2010): alpha- and gamma-Hexachlorocyclohexane measurements in the brine fraction of sea ice in the Canadian High Arctic using a sump-hole technique. Environmental Science & Technology, 44(24), 9258-9264

• Main Authors: Pućko, Monika, Stern, Gary A, Macdonald, Robie W, Barber, David G
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2010
• Subjects: International Polar Year 2007-2008 IPY; Arctic; International Polar Year; IPY; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.818639; https://doi.pangaea.de/10.1594/PANGAEA.818639

We used holes augered partially into first-year sea ice (sumps) to determine a- and g-HCH concentrations in sea-ice brine. The overwintering of the CCGS Amundsen in the Canadian western Arctic, as part of the Circumpolar Flaw Lead (CFL) System Study, provided the circumstances to allow brine to accumulate in sumps sufficiently to test the methodology. We show, for the first time, that as much as 50% of total HCHs in seawater can become entrapped within the ice crystal matrix. On average, in the winter first-year sea ice HCH brine concentrations reached 4.013 ± 0.307 ng/L and 0.423 ± 0.013 ng/L for the a- and g-isomer, respectively. In the spring, HCHs decreased gradually with time, with increasing brine volume fraction and decreasing brine salinity. These decreasing concentrations could be accounted for by both the dilution with the ice crystal matrix and under-ice seawater.We propose that the former process plays a more significant role considering brine volume fractions calculated in this study were below 20%. Levels of HCHs in the brine exceed under-ice water concentrations by approximately a factor of 3, a circumstance suggesting that the brine ecosystem has been, and continues to be, the most exposed to HCHs. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150