Carbonate system dynamics and biogeochemistry in a changing Arctic

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The Arctic is an important sink for atmospheric carbon dioxide, a powerful greenhouse gas. However, as the Arctic warms and the extent of summer sea ice declines (in a few decades, it is expected the summer Arctic Ocean will be ice free), it is not clear the degree to which this will change. The investigators will explore how carbon dioxide chemistry along the ice margins (marginal ice zone: MIZ) waters differ from that in the open ocean. Taking water samples on the RV Sikuliaq between May 20 to June 14, 2021, from the Bering sea to the MIZ in the Chukchi Sea, the investigators will measure several components of the carbon dioxide system in seawater, including the total concentration of carbon, and determine how much acidity the water can neutralize. This study will provide a better understanding of the complexities of arctic biogeochemistry and its changing role in carbon sequestration and ocean acidification in a warmer world. The investigators will produce a podcast series during the research cruise to share their experiences and findings for community science.Arctic Ocean summer sea ice is predicted to retreat such that in just a few decades the new norm will be ice-free summers. Taking water samples on the RV Sikuliaq between May 20 to June 14, 2021, from the Bering sea to the marginal ice zone in the Chukchi Sea, the area where open water becomes progressively more ice-covered (and ice melt is a significant signal), presents a unique opportunity to better understand the complexities in arctic biogeochemistry and its changing role in carbon sequestration as the summer ice edge recedes. By examining the internal consistency of the carbonate system/models, the work will lead to an improved understanding of the controls on ocean acidification and ocean-atmosphere CO2 exchange. The investigators will examine important carbonate system measurements such as dissolved organic and inorganic carbon, that when coupled with parallel mercury measurements being taken on the Sikuliaq, will improve our understanding of the relationships between dissolved elemental Hg and DIC in the Arctic, both in the open water and under the ice. The investigators will generate hands-on videos and materials for citizen science groups with a focus on polar regions. Finally, the investigators will create a cruise podcast series that will comprise five to ten minute podcasts for the public on the changing arctic, what it’s like to be a young oceanographer, and themes related to the study.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.