Presenter: Lauren Barrett (University of Connecticut)

Description:
The extent and duration of arctic sea ice is rapidly declining as the Arctic experiences disproportionately high warming due to climate change. Freshwater input and circulation in the Arctic Ocean are also changing as multi-year ice extent decreases. These changes raise uncertainty about the extent of the Arctic Ocean as a significant sink for atmospheric carbon dioxide, and the associated biogeochemical cycling of carbon. Crucial to our understanding of the Arctic carbon sink is the cycling and speciation of carbonate species, especially at the highly dynamic marginal ice zone where melting sea ice meets the open ocean. During a sampling effort in June 2021 aboard the R/V Sikuliaq, we measured dissolved inorganic carbon (DIC), total alkalinity (TA), the partial pressure of carbon dioxide (pCO­₂), pH, and carbonate ion concentration ([CO₃^2-]) throughout the Bering and Chukchi Seas in open water and under-ice water samples. The internal consistency of these variables will be assessed using CO2SYS software. This analysis will compare each parameter pairing for calculations of other variables in these dynamic waters, which will help inform future investigations. This study also provides novel direct observations of [CO₃^2-] and thus of the calcium carbonate saturation state (Ω).