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Carbonate chemistry of an in-situ free-ocean CO2 enrichment experiment (antFOCE) in comparison to short term variation in Antarctic coastal waters

Citation

Stark, JS and Roden, NP and Johnstone, GJ and Milnes, M and Black, JG and Whiteside, S and Kirkwood, W and Newbery, K and Stark, S and van Ooijen, E and Tilbrook, B and Peltzer, ET and Berry, K and Roberts, D, Carbonate chemistry of an in-situ free-ocean CO2 enrichment experiment (antFOCE) in comparison to short term variation in Antarctic coastal waters, Scientific Reports, 8, (1) Article 2816. ISSN 2045-2322 (2018) [Refereed Article]


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Copyright 2018 the author. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.1038/s41598-018-21029-1

Abstract

Free-ocean CO2 enrichment (FOCE) experiments have been deployed in marine ecosystems to manipulate carbonate system conditions to those predicted in future oceans. We investigated whether the pH/carbonate chemistry of extremely cold polar waters can be manipulated in an ecologically relevant way, to represent conditions under future atmospheric CO2 levels, in an in-situ FOCE experiment in Antarctica. We examined spatial and temporal variation in local ambient carbonate chemistry at hourly intervals at two sites between December and February and compared these with experimental conditions. We successfully maintained a mean pH offset in acidified benthic chambers of −0.38 (±0.07) from ambient for approximately 8 weeks. Local diel and seasonal fluctuations in ambient pH were duplicated in the FOCE system. Large temporal variability in acidified chambers resulted from system stoppages. The mean pH, Ωarag and fCO2 values in the acidified chambers were 7.688 ± 0.079, 0.62 ± 0.13 and 912 ± 150 µatm, respectively. Variation in ambient pH appeared to be mainly driven by salinity and biological production and ranged from 8.019 to 8.192 with significant spatio-temporal variation. This experiment demonstrates the utility of FOCE systems to create conditions expected in future oceans that represent ecologically relevant variation, even under polar conditions.

Item Details

Item Type:Refereed Article
Keywords:carbonate chemistry, CO2, antFOCE, Antarctica
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Chemical Oceanography
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Antarctic and Sub-Antarctic Oceanography
UTAS Author:Roden, NP (Mr Nick Roden)
UTAS Author:Black, JG (Mr James Black)
UTAS Author:Tilbrook, B (Dr Bronte Tilbrook)
UTAS Author:Roberts, D (Dr Donna Roberts)
ID Code:131896
Year Published:2018
Web of Science® Times Cited:4
Deposited By:Oceans and Cryosphere
Deposited On:2019-04-11
Last Modified:2019-05-01
Downloads:2 View Download Statistics

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