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| Titel |
Seasonal and inter-annual variability of air-sea CO2 fluxes and seawater carbonate chemistry in the Southern Bight of the North Sea |
| VerfasserIn |
Nathalie Gypens, Geneviève Lacroix, Christiane Lancelot, Alberto V. Borges |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250042618
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| Zusammenfassung |
| A 3D coupled biogeochemical-hydrodynamical model (MIRO-CO2&CO) has been
implemented in the English Channel (ECH) and the Southern Bight of the North Sea
(SBNS) to estimate the present-day spatio-temporal distribution of air-sea CO2
fluxes, surface water partial pressure of CO2 (pCO2) and other components of the
carbonate system (pH, saturation state of calcite (Ωca) and of aragonite (Ωar)) and the
main drivers of their variability. Model simulations performed from 1994 to 2004
show higher seasonal variability and horizontal gradients of air-sea CO2 fluxes
and seawater carbonate chemistry variables in near-shore waters than in off-shore
waters. This results from important river inputs of nutrients and carbon. Nutrients, by
stimulating primary production, drive a sink of atmospheric CO2 and an increase of
pH, of Ωca and of Ωar, while the input of organic and inorganic carbon, drive a
source of CO2 to the atmosphere and an decrease of pH, of Ωca and of Ωar. For the
1994-2004 period, air-sea CO2 fluxes show significant inter-annual variability, with
oscillations between annual CO2 sink and source. The inter-annual variability of
air-sea CO2 fluxes simulated in the SBNS is controlled primarily by river loads and
changes of primary production (net autotrophy in spring and early summer, and
net heterotrophy in winter and autumn), while in areas not influenced by rivers
as the ECH, the inter-annual variations of air-sea CO2 fluxes are mainly due to
changes in sea surface temperature and in near-surface wind strength and direction. |
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