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| Titel |
Glacial meltwater and primary production are drivers of strong CO2 uptake in fjord and coastal waters adjacent to the Greenland Ice Sheet |
| VerfasserIn |
L. Meire, D. H. Søgaard, J. Mortensen, F. J. R. Meysman, K. Soetaert, K. E. Arendt, T. Juul-Pedersen, M. E. Blicher, S. Rysgaard |
| 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 ; 12, no. 8 ; Nr. 12, no. 8 (2015-04-21), S.2347-2363 |
| Datensatznummer |
250117905
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| Publikation (Nr.) |
 copernicus.org/bg-12-2347-2015.pdf |
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| Zusammenfassung |
| The Greenland Ice Sheet releases large amounts of freshwater, which
strongly influences the physical and chemical properties of the
adjacent fjord systems and continental shelves. Glacial meltwater
input is predicted to strongly increase in the future, but the
impact of meltwater on the carbonate dynamics of these productive
coastal systems remains largely unquantified. Here we present
seasonal observations of the carbonate system over the year 2013 in the surface waters of a
west Greenland fjord (Godthåbsfjord) influenced by tidewater outlet glaciers. Our data reveal that
the surface layer of the entire fjord and adjacent continental shelf
are undersaturated in CO2 throughout the year. The average annual CO2
uptake within the fjord is estimated to be 65 g C m−2 yr−1, indicating that the fjord system is
a strong sink for CO2. The largest CO2 uptake occurs in the inner fjord near
to the Greenland Ice Sheet and high glacial meltwater input during the summer
months correlates strongly with low pCO2 values.
This strong CO2 uptake can be explained by the thermodynamic effect
on the surface water pCO2 resulting from the mixing of fresh glacial meltwater and ambient saline fjord water,
which results in a CO2 uptake of 1.8 mg C kg−1 of glacial ice melted.
We estimated that 28% of the CO2 uptake can be attributed to the input
of glacial meltwater, while the remaining part is due to high primary production.
Our findings imply that glacial melt\-water is an important driver for undersaturation in CO2
in fjord and coastal waters adjacent to large ice sheets. |
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