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| Titel |
Evidence for surface organic matter modulation of air-sea CO2 gas exchange |
| VerfasserIn |
M. Ll. Calleja, C. M. Duarte, Y. T. Prairie, S. Agustí  , G. J. Herndl |
| 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. 6 ; Nr. 6, no. 6 (2009-06-25), S.1105-1114 |
| Datensatznummer |
250003842
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| Publikation (Nr.) |
 copernicus.org/bg-6-1105-2009.pdf |
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| Zusammenfassung |
| Air-sea CO2 exchange depends on the air-sea CO2 gradient and the
gas transfer velocity (k), computed as a function of wind speed. Large
discrepancies among relationships predicting k from wind suggest that other
processes also contribute significantly to modulate CO2 exchange. Here
we report, on the basis of the relationship between the measured gas
transfer velocity and the organic carbon concentration at the ocean surface,
a significant role of surface organic matter in suppressing air-sea gas
exchange, at low and intermediate winds, in the open ocean, confirming
previous observations. The potential role of total surface organic matter
concentration (TOC) on gas transfer velocity (k) was evaluated by direct
measurements of air-sea CO2 fluxes at different wind speeds and
locations in the open ocean. According to the results obtained, high surface
organic matter contents may lead to lower air-sea CO2 fluxes, for a
given air-sea CO2 partial pressure gradient and wind speed below
5 m s−1, compared to that observed at low organic matter contents. We found
the bias in calculated gas fluxes resulting from neglecting TOC to co-vary
geographically and seasonally with marine productivity. These results
support previous evidences that consideration of the role of organic matter
in modulating air-sea CO2 exchange may improve flux estimates and help
avoid possible bias associated to variability in surface organic
concentration across the ocean. |
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