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1K - Tropospheric Fate (MO13/5) Investigating the occurrence and dynamics of PCBs and PCNs between Arctic snow and air. Herbert, Ben1, Halsall, Crispin1, Fitzpatrick, Lisa1, Jones, Kevin1, Thomas, Gareth1, Kallenborn, Roland2, 1 Environmental Science Dept, Lancaster University, Lancaster, Lancashire, England2 Norwegian Institute for Air Research, The Polar Environment Centre, Tromoso, Tromoso, Norway ABSTRACT- As part of a short-term investigation into air/snow exchange of POPs, simultaneous air and surface snow samples were taken consecutively over six days at Ny- Key words: POP, Arctic, Air, Snowpack |
lesund in the Norwegian Arctic during April 2001. Snow samples were collected using novel high volume (50 L) aluminium snow cans and air samples using a Hi-Vol air sampler. Concentrations of PCBs and PCNs in the fresh snowpack varied between snowfall episodes significantly (PCBs: by a factor of∼17), unlike air concentrations that displayed relatively lower variation (PCBs: factor of ∼1.1) throughout the sampling period. However air concentrations were notably higher than those observed in the Canadian Arctic, with PCBs ranging from 28.3-33.1 pg m-3 and PCNs 27.2-48.3 pg m-3. The lowest density snow revealed the highest PCB concentrations with significant contributions by the penta- and hexa-chlorinated homologues. The PCNs, on the other hand, were dominated by the lighter tri- and tetra homologues with concentrations ∼55% less than the PCBs (mean PCB snow 740pg L-1 and PCN 488 pg L-1). Re-sampling of an aged snow layer, 24-h after initial snowfall, revealed a relative enrichment in the heavier congeners. Further results from this work suggest considerable snow pack dynamics immediately following snowfall, with important implications for the fate of these chemicals in the Arctic region.