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| Titel |
Air-Sea CO2 fluxes on the Scotian Shelf: seasonal to multi-annual variability |
| VerfasserIn |
E. H. Shadwick, H. Thomas, A. Comeau, S. E. Craig, C. W. Hunt, J. E. Salisbury |
| 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 ; 7, no. 11 ; Nr. 7, no. 11 (2010-11-26), S.3851-3867 |
| Datensatznummer |
250005074
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| Publikation (Nr.) |
 copernicus.org/bg-7-3851-2010.pdf |
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| Zusammenfassung |
| We develop an algorithm to compute pCO2 in the Scotian Shelf region (NW Atlantic) from satellite-based
estimates of chlorophyll-a concentration, sea-surface temperature, and observed wind speed. This algorithm
is based on a high-resolution time-series of pCO2 observations from an autonomous mooring. At the mooring
location (44.3° N and 63.3° W), the surface waters act as a source of CO2 to the
atmosphere over the annual scale, with an outgassing of −1.1 mol C m−2 yr−1 in 2007/2008. A hindcast
of air-sea CO2 fluxes from 1999 to 2008 reveals significant variability both spatially and from year
to year. Over the decade, the shelf-wide annual air-sea fluxes range from an outgassing of −1.70 mol C m−2 yr−1
in 2002, to −0.02 mol C m−2 yr−1 in 2006. There is a gradient in the air-sea
CO2 flux between the northeastern Cabot Strait region which acts as a net sink of CO2 with an annual
uptake of 0.50 to 1.00 mol C m−2 yr−1, and the southwestern Gulf of Maine region which acts as a
source ranging from −0.80 to −2.50 mol C m−2 yr−1. There is a decline, or a negative trend, in
the air-sea pCO2 gradient of 23 μatm over the decade, which can be explained by a cooling of
1.3 °C over the same period. Regional conditions govern spatial, seasonal, and interannual
variability on the Scotian Shelf, while multi-annual trends appear to be influenced by larger scale
processes. |
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