| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Increase in ocean acidity variability and extremes under increasing atmospheric CO2
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| Autores: |
Burger, Friedrich A.
John, Jasmin G.
Frolicher, Thomas L.
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| Data: |
2020-09
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| Ano: |
2020
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| Resumo: |
Ocean acidity extreme events are short-term periods of relatively high [H+] concentrations. The uptake of anthropogenic CO2 emissions by the ocean is expected to lead to more frequent and intense ocean acidity extreme events, not only due to changes in the long-term mean but also due to changes in short-term variability. Here, we use daily mean output from a five-member ensemble simulation of a comprehensive Earth system model under low- and high-CO2-emission scenarios to quantify historical and future changes in ocean acidity extreme events. When defining extremes relative to a fixed preindustrial baseline, the projected increase in mean [H+] causes the entire surface ocean to reach a near-permanent acidity extreme state by 2030 under both the low- and high-CO2-emission scenarios. When defining extremes relative to a shifting baseline (i.e., neglecting the changes in mean [H+]), ocean acidity extremes are also projected to increase because of the simulated increase in [H+] variability; e.g., the number of days with extremely high surface [H+] conditions is projected to increase by a factor of 14 by the end of the 21st century under the high-CO2-emission scenario relative to preindustrial levels. Furthermore, the duration of individual extreme events is projected to triple, and the maximal intensity and the volume extent in the upper 200 m are projected to quintuple. Similar changes are projected in the thermocline. Under the low-emission scenario, the increases in ocean acidity extreme-event characteristics are substantially reduced. At the surface, the increases in [H+] variability are mainly driven by increases in [H+] seasonality, whereas changes in thermocline [H+] variability are more influenced by interannual variability. Increases in [H+] variability arise predominantly from increases in the sensitivity of [H+] to variations in its drivers (i.e., carbon, alkalinity, and temperature) due to the increase in oceanic anthropogenic carbon. The projected increase in [H+] variability and extremes may enhance the risk of detrimental impacts on marine organisms, especially for those that are adapted to a more stable environment.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00676/78825/81141.pdf
https://archimer.ifremer.fr/doc/00676/78825/81142.pdf
DOI:10.5194/bg-17-4633-2020
https://archimer.ifremer.fr/doc/00676/78825/
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| Editor: |
Copernicus Gesellschaft Mbh
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| Relação: |
info:eu-repo/grantAgreement/EC/H2020/820989/EU//COMFORT
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| Formato: |
application/pdf
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| Fonte: |
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2020-09 , Vol. 17 , N. 18 , P. 4633-4662
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| Direitos: |
info:eu-repo/semantics/openAccess
restricted use
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