A multi-decadal delay in the onset of corrosive ‘acidified’ waters in the Ross Sea of Antarctica due to strong air-sea CO 2 disequilibrium

Ben Mcneil , Alessandro Tagliabue (1) , Colm Sweeney

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]

Antarctic coastal waters have an abundance of marine organisms that secrete the mineral aragonite for growth and survival. Increasing oceanic anthropogenic CO 2 uptake will push these waters to a point whereby aragonite will start to geochemically corrode, with direct consequences for the Antarctic ecosystem. Here we combine surface CO 2 data in the Ross Sea, Antarctica with a regional ocean/sea-ice model to better pinpoint the timing of corrosive conditions. Our analysis suggests sea-ice cover and deep-water entrainment during winter results in 65% lower storage of anthropogenic CO 2 in comparison to atmospheric CO 2 equilibrium. This means that instead of corrosive 'acidified' waters beginning as early as the winter of 2015, anthropogenic CO 2 disequilibrium delays its onset by up to 30 years, giving this Antarctic marine ecosystem a several decade reprieve to corrosive conditions. Our results demonstrate a broader importance of understanding natural oceanic carbon cycle variability for the onset of corrosive conditions. Citation: McNeil, B. I., A. Tagliabue, and C. Sweeney (2010), A multi-decadal delay in the onset of corrosive 'acidified' waters in the Ross Sea of Antarctica due to strong air-sea CO 2 disequilibrium,

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Ben Mcneil, Alessandro Tagliabue, Colm Sweeney. A multi-decadal delay in the onset of corrosive ‘acidified’ waters in the Ross Sea of Antarctica due to strong air-sea CO 2 disequilibrium. Geophysical Research Letters, 2010, 37 (19), pp.n/a-n/a. ⟨10.1029/2010GL044597⟩. ⟨hal-03200988⟩