Measurements of mercury distributions in sea ice cores have revealed elevated total mercury concentrations in sea ice relative to underlying seawater. Although field data are limited, total mercury concentrations also appear to be greatly enriched in surface layers of sea ice. We are continuing a multi-year study of experimental sea ice growth in order to determine the relative importance of: 1) overlying snowpack/atmospheric deposition versus seawater as the primary source of total mercury in surface sea ice; and 2) entrainment of particles versus brine inclusion as the primary mechanism of mercury incorporation into sea ice. Our results will help clarify the role of sea ice as an interface between atmospheric and oceanic mercury reservoirs. Furthermore, our results will help us better predict how climate-driven changes from multi-year to first-year sea ice coverage will influence mercury in the upper ocean due to seasonal sea ice melt.

Fieldwork site: Sea Ice Environmental Research Facility (SERF), University of Manitoba, Winnipeg (Canada)

PI: K.Munson/F.Wang

Project lead: K. Munson

Project Participants: Kathleen Munson, Yubin Hu, Deb Armstrong, James Singer, Fei Wang (CEOS)