Study of Sea Ice Biogeochemistry (snow depth, ice thickness, ice salinity, dissolved inorganic carbon, total alkalinity, biomass, under ice currents) Comparing a Thick First Year Ice Site, and a Thinner Polynya Site Near Cambridge Bay

This study is about the carbonate chemistry of sea ice. Sea ice carbonate chemistry is thought to play an important role in global carbon cycles (i.e the uptake and storage of carbon dioxide from the atmosphere) but exactly how important is subject to considerable debate. One of the reasons for this uncertainty is that there is considerable variability in the reported total alkalinity (TA) to total inorganic carbon (TIC) ratio between different studies. Usually, this disparity is explained by spatial variability - different sea ice sites experience different physical, biological, and chemical characteristics, leading to large variations in the TA:TIC ratio of sea ice. To study variability in sea ice TA and TIC, we selected a site about 30 km west of Cambridge Bay (Iqaluktuttiaq), Nunavut. The site is a known location of an 'invisible polynya', a location where strong under-ice currents lead to thinner ice and potentially higher ice algae biomass. We used two sites - one outside of the polynya, and one within the polynya - to perform a statistical comparison of TIC and TA. Our hypothesis was that due to the strong variations in physical (currents, ice thickness) and biological (ice algae) conditions, we would observe significant spatial variability in sea ice carbonate chemistry.