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| García-ibáñez, Maribel I.; Bates, Nicholas R.; Bakker, Dorothee C.e.; Fontela, Marcos; Velo, Antón. |
| The net uptake of carbon dioxide (CO2) from the atmosphere is changing the ocean's chemical state. Such changes, commonly known as ocean acidification, include a reduction in pH and the carbonate ion concentration ([CO32−]), which in turn lowers oceanic saturation states (Ω) for calcium carbonate (CaCO3) minerals. The Ω values for aragonite (Ωaragonite; one of the main CaCO3 minerals formed by marine calcifying organisms) influence the calcification rate and geographic distribution of cold-water corals (CWCs), important for biodiversity. Here, high-quality measurements, collected on thirteen cruises along the same track during 1991–2018, are used to determine the long-term changes in Ωaragonite in the Irminger and Iceland Basins of the North Atlantic... |
| Tipo: Text |
Palavras-chave: Ocean acidification; Aragonite saturation state; Atlantic Meridional Overturning Circulation; Eastern-Subpolar North Atlantic Ocean. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/79965/82895.pdf |
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| Fontela, Marcos; Garcia-ibanez, Maria Isabel; Hansell, Dennis A.; Mercier, Herle; Perez, Fiz F. |
| The quantitative role of the Atlantic Meridional Overturning Circulation (AMOC) in dissolved organic carbon (DOC) export is evaluated by combining DOC measurements with observed water mass transports. In the eastern subpolar North Atlantic, both upper and lower limbs of the AMOC transport high-DOC waters. Deep water formation that connects the two limbs of the AMOC results in a high downward export of non-refractory DOC (197 Tg-C center dot yr(-1)). Subsequent remineralization in the lower limb of the AMOC, between subpolar and subtropical latitudes, consumes 72% of the DOC exported by the whole Atlantic Ocean. The contribution of DOC to the carbon sequestration in the North Atlantic Ocean (62 Tg-C center dot yr(-1)) is considerable and represents almost a... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00342/45298/44754.pdf |
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| Perez, Fiz F; Fontela, Marcos; Garcia-ibanez, Maria Isabel; Mercier, Herle; Velo, Anton; Lherminier, Pascale; Zunino, Patricia; De La Paz, Mercedes; Alonso-perez, Fernando; Guallart, Elisa E.; Padin, Xose A.. |
| Since the Industrial Revolution, the North Atlantic Ocean has been accumulating anthropogenic carbon dioxide (CO2) and experiencing ocean acidification1, that is, an increase in the concentration of hydrogen ions (a reduction in pH) and a reduction in the concentration of carbonate ions. The latter causes the ‘aragonite saturation horizon’—below which waters are undersaturated with respect to a particular calcium carbonate, aragonite—to move to shallower depths (to shoal), exposing corals to corrosive waters2,3. Here we use a database analysis to show that the present rate of supply of acidified waters to the deep Atlantic could cause the aragonite saturation horizon to shoal by 1,000–1,700 metres in the subpolar North Atlantic within the next three... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00426/53783/55106.pdf |
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| Fontela, Marcos; Perez, Fiz F; Carracedo, Lidia; Padín, Xosé A.; Velo, Antón; García-ibañez, Maribel I.; Lherminier, Pascale. |
| The oceanic uptake of atmospheric carbon dioxide (CO2) emitted by human activities alters the seawater carbonate system. Here, the chemical status of the Northeast Atlantic is examined by means of a high-quality database of carbon variables based on the GO-SHIP A25 section (1997–2018). The increase of atmospheric CO2 leads to an increase in ocean anthropogenic carbon (Cant) and a decrease in carbonate that is unequivocal in the upper and mid-layers (0–2,500 m depth). In the mid-layer, the carbonate content in the Northeast Atlantic is maintained by the interplay between the northward spreading of recently conveyed Mediterranean Water with excess of carbonate and the arrival of subpolar-origin waters close to carbonate undersaturation. In this study we show... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00646/75822/76790.pdf |
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