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| Titel |
Identifying the responses of the carbonate system and its governing processes in three high latitude shelf seas: Barents Sea, North Sea and Baltic Sea. |
| VerfasserIn |
Rocío Castaño-Primo, Corinna Schrum, Ute Daewel, Helmuth Thomas, Cara Nissen |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250096579
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| Publikation (Nr.) |
 EGU/EGU2014-12089.pdf |
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| Zusammenfassung |
| The increasing concentration of atmospheric CO2 is the main driver for the long-term trends
in the ocean carbon chemistry on a global scale. However, this signal is modulated at
regional scales by the physical and ecological dynamics of the area. Circulation,
temperature and primary production modify pCO2 in the water either directly or
indirectly via alkalinity or DIC. The contribution of the individual processes to
the overall changes varies in different regional settings. The aim of this work is
to identify and describe the specific regional responses of the carbonate system
to several forcings in three distinct ecosystems in the North Atlantic (the North
Sea, the Baltic Sea and the Barents Sea) and on inter-annual to multi-decadal time
scales.
Despite their relative geographical proximity, these shelf systems exhibit very different
dynamics. The North and Barents Seas receive important inflows of Atlantic waters, while the
Baltic Sea is an almost enclosed system, with very little inflow from the North Sea. Wind,
tides, freshwater supply and ice cover act very differently in the three systems, but
dominantly structure the ecosystem dynamics on spatial and temporal scales. These particular
features have a strong impact in the biogeochemical cycles and ultimately shape the
variations in the carbonate chemistry.
Here the ECOSMO model was employed for a 60-year period (1947-2007). ECOSMO is
a 3-D coupled physical-biogeochemical model including a carbon chemistry module. The
biogeochemical model resolves the cycles of nitrogen, phosphorus and silicate,
includes 3 functional groups of phytoplankton and 2 groups of zooplankton. pH and
pCO2 are calculated from alkalinity and DIC, which are prognostic variables in the
model.
The model output for alkalinity, DIC, pH and pCO2 is compared and validated with
observations available in several databases. Additionally, the model sensitivity is tested with
respect to the boundary conditions of alkalinity and DIC. |
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