1526 / 2024-09-27 21:47:37

Modeling the impact of sea ice on the marine carbon cycle in the Bering Sea

Arctic,sea ice,carbon cycling,Bering Sea,Ocean acidification

Arctic and subarctic ocean waters remove considerable carbon dioxide from the atmosphere and mitigate climate change. Meanwhile, the marine carbonate system is in turn influenced by climate change, such as through rapid sea ice melt. Therefore, it is crucial to understand the sea ice mechanism and how its seasonal variations affect the marine carbon cycles. Historically, sea ice extent and the timing of ice retreat are highly variable in the Bering Sea, especially over the last three decades which have seen several multi-year periods of unusually high and low ice conditions. The wide variability over this timeframe offers a unique opportunity to examine the effects of sea ice on the marine carbon system. We use a regional ocean biogeochemical model configured to the Bering Sea to investigate how sea ice dynamics impact critical ocean carbonate parameters in this region. This model incorporates a sea-ice carbon pump mechanism which transports dissolved inorganic carbon and total alkalinity to subsurface waters during sea ice formation, and dilutes surface waters during sea ice retreat. We also use a set of high-resolution observations from autonomous surface vehicles to assess the model performance. The goal is to assess model skill and develop improved parameterizations for simulating the effect of sea ice on the seasonal carbon cycle. These efforts will further enhance ongoing work to support Alaskan stakeholders and decision makers by providing high-resolution predictions and projections of ocean acidification.