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| Titel |
Air-Sea CO2 fluxes in the Atlantic as measured during boreal spring and autumn |
| VerfasserIn |
X. A. Padin, M. Vázquez-Rodríguez, M. Castaño, A. Velo, F. Alonso-Pérez, J. Gago, M. Gilcoto, M. Álvarez, P. C. Pardo, M. Paz, A. F. Ríos, 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 ; 7, no. 5 ; Nr. 7, no. 5 (2010-05-18), S.1587-1606 |
| Datensatznummer |
250004771
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| Publikation (Nr.) |
 copernicus.org/bg-7-1587-2010.pdf |
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| Zusammenfassung |
| A total of fourteen hydrographic cruises from 2000 to 2008
were conducted during the spring and autumn seasons between Spain and the
Southern Ocean under the framework of the Spanish research project FICARAM.
The underway measurements were processed and analysed to describe the
meridional air-sea CO2 fluxes (FCO2) in the covered sector of the
Atlantic Ocean. The data has been grouped into different biogeochemical
oceanographic provinces based on thermohaline characteristics. The spatial
and temporal distributions of FCO2 followed expected distributions and
annual trends reproducing the recent climatological ΔfCO2
estimations with a mean difference of −3 ± 18 μatm (Takahashi et
al., 2009). The reduction in the CO2 saturation along the meridional
FICARAM cruises represented an increase of 0.02 ± 0.14 mol m−2 yr−1
in the ocean uptake of atmospheric CO2. The subtropical
waters in both Hemispheres acted as a sink of atmospheric CO2 during
the successive spring seasons and as a source in autumn. The coarse
reduction of the ocean uptake of atmospheric CO2 observed in the North
Atlantic Ocean was linked to conditions of negative phase of the North
Atlantic Oscillation that prevailed during the FICARAM period. Surface
waters in the North Equatorial Counter Current revealed a significant
long-term decrease of sea surface salinity of −0.16 ± 0.01 yr−1
coinciding with a declination of −3.5 ± 0.9 μatm yr−1 in the
air–sea disequilibrium of CO2 fugacity and a rise of oceanic CO2
uptake of −0.09 ± 0.03 mol m−2 yr−1. The largest CO2
source was located in the equatorial upwelling system. These tropical waters
that reached emissions of 0.7 ± 0.5 and 1.0 ± 0.7 mol m−2 y−1
in spring and autumn, respectively, showed an interannual warming
of 0.11 ± 0.03 °C yr−1 and a wind speed decrease of −0.58 ± 0.14 m s−1 yr−1
in spring cruises which suggest the weakening of
upwelling events associated with warm El Niño – Southern Oscillation
episodes. Contrary the surface waters of the Patagonian Sea behaved as an
intense sink of CO2 in March and November. The oceanic waters of the
convergence of Falkland and Brazil Currents showed the strongest CO2
absorption with a rate of −5.4 ± 3.6 mol m−2 yr−1 in November.
The Southern Oceans sampled in the Drake Passage behave as an average uptake
rate of −1.1 ± 0.9 mol m−2 yr−1 while the distal shelf of the
Livingston Island acted as a slight source of CO2 to the atmosphere. |
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