Calcium carbonate saturation states along the West Antarctic Peninsula

The waters along the West Antarctic Peninsula (WAP) have experienced warming and increased freshwater inputs from melting sea ice and glaciers in recent decades. Challenges exist in understanding the consequences of these changes on the inorganic carbon system in this ecologically important and high...

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Bibliographic Details
Published in:Antarctic Science
Main Authors: Jones, E.M., Hoppema, M., Bakker, K., de Baar, H.J.W.
Format: Article in Journal/Newspaper
Language:English
Published: 2021
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Online Access:https://www.vliz.be/imisdocs/publications/52/371752.pdf
Description
Summary:The waters along the West Antarctic Peninsula (WAP) have experienced warming and increased freshwater inputs from melting sea ice and glaciers in recent decades. Challenges exist in understanding the consequences of these changes on the inorganic carbon system in this ecologically important and highly productive ecosystem. Distributions of dissolved inorganic carbon (C T ), total alkalinity (A T ) and nutrients revealed key physical, biological and biogeochemical controls of the calcium carbonate saturation state (Ω aragonite ) in different water masses across the WAP shelf during the summer. Biological productionin spring and summer dominated changes in surface water Ω aragonite (ΔΩ aragonite up to +1.39; ~ 90%) relative to underlying Winter Water. Sea-ice and glacial meltwaterconstituted a minor source of A T that increased surface water Ω aragonite (ΔΩ aragonite up to +0.07; ~ 13%). Remineralization of organic matter and an influx of carbon-rich brines led to cross-shelf decreases in Ω aragonite in Winter Water and Circumpolar Deep Water. A strong biological carbon pump over the shelf created Ω aragonite oversaturation in surface waters and suppression of Ω aragonite in subsurface waters. Undersaturation of aragonite occurred at < ~1000 m. Ongoing changes along the WAP will impact the biologically driven and meltwater-driven processes that influence the vulnerability of shelf waters to calcium carbonate undersaturation in the future.