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| Titel |
Modern decrease of δ¹⁸O in Mediterranean sediments over the last 150 y: anthropogenic forcing and natural variability |
| VerfasserIn |
S. Alessio, C. Taricco, G. Vivaldo, M. Ghil |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066503
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| Zusammenfassung |
| Our previous work (Taricco et al., 2009) has documented a high-resolution record of
foraminiferal δ18O isotopic ratio that covers the last two millennia. This record was obtained
from a shallow-water sediment core drilled in the Central Mediterranean (Gallipoli Terrace in
the Gulf of Taranto, Ionian Sea), and dated with high accuracy by tephroanalysis and
radiometric measurements. The δ18O series so obtained spans the last 2200 years and shows
a steep decrease during the Industrial Era.
We use here pre-industrial δ18O variations to design and tune algorithms able to forecast
the natural variability in the δ18O series over the last 150 y (Alessio et al., 2012).
Autoregressive (AR) models and feed-forward neural networks are applied to the highly
significant components revealed by Singular Spectrum Analysis (SSA). Comparison between
the forecast and the actual δ18O signal during the Industrial Era shows that the natural
contribution to the modern δ18O variation decreased gradually, until it reached roughly 40%
as early as the end of the 1970s.
References
Taricco C., Ghil M., Alessio S., and Vivaldo G., 2009. Two millennia of climate
variability in the Central Mediterranean, Clim. Past, 5, 171–181.
Alessio S., Vivaldo G., Taricco C., Ghil M., 2012. Natural Variability and Anthropogenic
Effects in a Central Mediterranean Core, Clim. Past, submitted. |
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