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Titel |
Anthropogenic and natural CO2 exchange through the Strait of Gibraltar |
VerfasserIn |
I. E. Huertas, A. F. Ríos, J. García-Lafuente, A. Makaoui, S. Rodríguez-Gálvez, A. Sánchez-Román, A. Orbi, J. Ruíz, F. F. Pérez |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 6, no. 4 ; Nr. 6, no. 4 (2009-04-23), S.647-662 |
Datensatznummer |
250003645
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Publikation (Nr.) |
copernicus.org/bg-6-647-2009.pdf |
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Zusammenfassung |
The exchange of both anthropogenic and natural inorganic carbon between the
Atlantic Ocean and the Mediterranean Sea through Strait of Gibraltar was
studied for a period of two years under the frame of the CARBOOCEAN project.
A comprehensive sampling program was conducted, which was design to collect
samples at eight fixed stations located in the Strait in successive cruises
periodically distributed through the year in order to ensure a good spatial
and temporal coverage. As a result of this monitoring, a time series namely
GIFT (GIbraltar Fixed Time series) has been
established, allowing the generation of an extensive data set of the carbon
system parameters in the area. Data acquired during the development of nine
campaigns were analyzed in this work. Total inorganic carbon concentration
(CT) was calculated from alkalinity-pHT pairs and appropriate
thermodynamic relationships, with the concentration of anthropogenic carbon
(CANT) being also computed using two methods, the ΔC* and the
TrOCA approach. Applying a two-layer model of water mass exchange through
the Strait and using a value of −0.85 Sv for the average transport of the
outflowing Mediterranean water recorded in situ during the considered period, a net
export of inorganic carbon from the Mediterranean Sea to the Atlantic was
obtained, which amounted to 25±0.6 Tg C yr−1. A net alkalinity
output of 16±0.6 Tg C yr−1 was also
observed to occur through the Strait. In contrast, the Atlantic water was
found to contain a higher concentration of anthropogenic carbon than the
Mediterranean water, resulting in a net flux of CANT towards the
Mediterranean basin of 4.20±0.04 Tg C yr−1 by using the
ΔC* method, which constituted the most adequate approach for this
environment. A carbon balance in the Mediterranean was assessed and fluxes
through the Strait are discussed in relation to the highly diverse estimates
available in the literature for the area and the different approaches
considered for CANT estimation. This work unequivocally confirms the
relevant role of the Strait of Gibraltar as a controlling point for the
biogeochemical exchanges occurring between the Mediterranean Sea and the
Atlantic Ocean and emphasizes the influence of the Mediterranean basin in
the carbon inventories of the North Atlantic. |
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