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Titel |
Twentieth century δ¹³C variability in surface water dissolved inorganic carbon recorded by coralline algae in the northern North Pacific Ocean and the Bering Sea |
VerfasserIn |
B. Williams, J. Halfar, R. S. Steneck, U. G. Wortmann, S. Hetzinger, W. Adey, P. Lebednik, M. Joachimski |
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 ; 8, no. 1 ; Nr. 8, no. 1 (2011-01-24), S.165-174 |
Datensatznummer |
250005352
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Publikation (Nr.) |
copernicus.org/bg-8-165-2011.pdf |
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Zusammenfassung |
The oxygen isotopic composition and Mg/Ca ratios in the skeletons of
long-lived coralline algae record ambient seawater temperature over time.
Similarly, the carbon isotopic composition in the skeletons record δ13C values of ambient seawater dissolved inorganic carbon. Here,
we measured δ13C in the coralline alga Clathromorphum nereostratum to test the feasibility
of reconstructing the intrusion of anthropogenic CO2 into the northern
North Pacific Ocean and Bering Sea. The δ13C was measured in
the high Mg-calcite skeleton of three C. nereostratum specimens from two islands 500 km
apart in the Aleutian archipelago. In the records spanning 1887 to 2003, the
average decadal rate of decline in δ13C values increased from
0.03‰ yr−1 in the 1960s to 0.095‰ yr−1 in the 1990s, which was
higher than expected due to solely the δ13C-Suess effect.
Deeper water in this region exhibits higher concentrations of CO2 and
low δ13C values. Transport of deeper water into surface water
(i.e., upwelling) increases when the Aleutian Low is intensified. We
hypothesized that the acceleration of the δ13C decline may
result from increased upwelling from the 1960s to 1990s, which in turn was
driven by increased intensity of the Aleutian Low. Detrended δ13C records also varied on 4–7 year and bidecadal timescales
supporting an atmospheric teleconnection of tropical climate patterns to the
northern North Pacific Ocean and Bering Sea manifested as changes in
upwelling. |
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