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Lauvset, S. K.; Carter, B. R.; Perez, Ff; Jiang, L-q; Feely, R. A.; Velo, A.; Olsen, A.. |
Ocean acidification evolves on the background of a natural ocean pH gradient that is the result of the interplay between ocean mixing, biological production and remineralization, calcium carbonate cycling, and temperature and pressure changes across the water column. While previous studies have analyzed these processes and their impacts on ocean carbonate chemistry, none have attempted to quantify their impacts on interior ocean pH globally. Here we evaluate how anthropogenic changes and natural processes collectively act on ocean pH, and how these processes set the vulnerability of regions to future changes in ocean acidification. We use the mapped data product from the Global Ocean Data Analysis Project version 2, a novel method to estimate preformed... |
Tipo: Text |
Palavras-chave: PH; Remineralization; CaCO3; Anthropogenic; Global ocean. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78793/81066.pdf |
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Sulpis, Olivier; Boudreau, Bernard P.; Mucci, Alfonso; Jenkins, Chris; Trossman, David S.; Arbic, Brian K.; Key, Robert M.. |
Oceanic uptake of anthropogenic CO2 leads to decreased pH, carbonate ion concentration, and saturation state with respect to CaCO3 minerals, causing increased dissolution of these minerals at the deep seafloor. This additional dissolution will figure prominently in the neutralization of man-made CO2 . However, there has been no concerted assessment of the current extent of anthropogenic CaCO3 dissolution at the deep seafloor. Here, recent databases of bottom-water chemistry, benthic currents, and CaCO3 content of deep-sea sediments are combined with a rate model to derive the global distribution of benthic calcite dissolution rates and obtain primary confirmation of an anthropogenic component. By comparing preindustrial with present-day rates, we determine... |
Tipo: Text |
Palavras-chave: Ocean acidification; Seafloor; CaCO3; Dissolution; Anthropogenic CO2. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00675/78677/80887.pdf |
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Lorrain, A.; Clavier, J.; Thebault, J.; Tremblay-boyer, L.; Houlbreque, F.; Amice, E.; Le Goff, M.; Chauvaud, L.. |
Researchers often use metabolic measurements in the field over narrow time periods to estimate an organism's metabolism over large time scales. Here, we measured in situ respiration, calcification and excretion rates of the tropical gastropod Tectus niloticus L. through benthic chamber experiments. Our samples spanned a 21 h time frame and were taken during both the warm and cool seasons. We assessed diel and seasonal variability in metabolic rates, as well as the effect of individual size and the contribution of shell epi-and endobionts. Our results show that metabolic rates vary through time at both diel and seasonal scales, as measured fluxes for respiration and calcification were significantly higher at night during the warm season. This nocturnal... |
Tipo: Text |
Palavras-chave: Gastropod; Seasonal variations; Diel variations; Size; Carbon fluxes; CO2; CaCO3; New Caledonia. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00256/36675/39633.pdf |
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