Vertical profiles of bromoform in snow, sea ice, and seawater in the Canadian Arctic

摘要: Bromoform (CHBr3) was measured in vertical profiles from the snow surface through snowpack, sea ice, and water column to seafloor at Resolute Bay, Canada, spring of 1992. Elevated concentrations bromoform were observed both ice (32–266 ng L−1 by liquid volume) seawater (∼20 L−1) ice-water interface, associated with emission microalgae. A surprising finding a second horizon high (336–367 snow-ice interface. Chlorophyll salinity also elevated this upper layer, although chlorophyll much lower than basal microalgal layer. We speculate that bromoform-enriched layer may have originated scavenging frazil during initial formation preceding autumn. Equally unexpected occurrence yet higher snowpack immediately overlying (492–1260 L−1), declining concentration (by about factor 2 or more) toward surface. Snow very recent origin, however, contained as little orders magnitude less older snowpack. Possible origins for include diffusion out gradual atmosphere adsorption on crystals. These are considered turn. In one scenario, photolysis is considered, which might help account atmospheric bromine-ozone chemistry. The possible contributions snow, levels winter it concluded presents most significant reservoir bromoform.