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| Titel |
Controls of Caribbean surface hydrology during the mid- to late Holocene: insights from monthly resolved coral records |
| VerfasserIn |
C. Giry, T. Felis, M. Kölling, W. Wei, G. Lohmann, S. Scheffers |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 2 ; Nr. 9, no. 2 (2013-03-22), S.841-858 |
| Datensatznummer |
250018023
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| Publikation (Nr.) |
 copernicus.org/cp-9-841-2013.pdf |
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| Zusammenfassung |
| Several proxy-based and modeling studies have investigated long-term changes
in Caribbean climate during the Holocene, however, very little is known on
its variability on short timescales. Here we reconstruct seasonality and
interannual to multidecadal variability of sea surface hydrology of the
southern Caribbean Sea by applying paired coral Sr/Ca and δ18O
measurements on fossil annually banded Diploria strigosa corals from Bonaire. This allows for
better understanding of seasonal to multidecadal variability of the Caribbean
hydrological cycle during the mid- to late Holocene. The monthly resolved
coral Δδ18O records are used as a proxy for the oxygen
isotopic composition of seawater (δ18Osw) of the southern
Caribbean Sea. Consistent with modern day conditions, annual
δ18Osw cycles reconstructed from three modern corals reveal that
freshwater budget at the study site is influenced by both net precipitation
and advection of tropical freshwater brought by wind-driven surface
currents. In contrast, the annual δ18Osw cycle
reconstructed from a mid-Holocene coral indicates a sharp peak towards more
negative values in summer, suggesting intense summer precipitation at 6 ka BP
(before present). In line with this, our model simulations indicate that
increased seasonality of the hydrological cycle at 6 ka BP results from
enhanced precipitation in summertime. On interannual to multidecadal
timescales, the systematic positive correlation observed between
reconstructed sea surface temperature and salinity suggests that freshwater
discharged from the Orinoco and Amazon rivers and transported into the
Caribbean by wind-driven surface currents is a critical component
influencing sea surface hydrology on these timescales. |
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