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Titel |
Holocene climate variability in north-eastern Italy: potential influence of the NAO and solar activity recorded by speleothem data |
VerfasserIn |
D. Scholz, S. Frisia, A. Borsato, Christoph Spötl, J. Fohlmeister, M. Mudelsee, R. Miorandi, A. Mangini |
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 ; 8, no. 4 ; Nr. 8, no. 4 (2012-08-27), S.1367-1383 |
Datensatznummer |
250005718
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Publikation (Nr.) |
copernicus.org/cp-8-1367-2012.pdf |
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Zusammenfassung |
Here we present high-resolution stable isotope and lamina thickness profiles
as well as radiocarbon data for the Holocene stalagmite ER 76 from
Grotta di Ernesto (north-eastern Italy), which was dated by combined
U-series dating and lamina counting. ER 76 grew between 8 ka (thousands of
years before 2000 AD) and today, with a hiatus from 2.6 to 0.4 ka.
Data from nine meteorological stations in Trentino show a significant
influence of the North Atlantic Oscillation (NAO) on winter temperature and
precipitation in the cave region. Spectral analysis of the stable isotope
signals of ER 76 reveals significant peaks at periods of 110, 60–70, 40–50,
32–37 and around 25 a. Except for the cycle between 32 and 37 a all
periodicities have corresponding peaks in power spectra of solar
variability, and the 25-a cycle may correspond to NAO variability. This
suggests that climate variability in northern Italy was influenced by both
solar activity and the NAO during the Holocene.
Six periods of warm winter climate in the cave region were identified. These
are centred at 7.9, 7.4, 6.5, 5.5, 4.9 and 3.7 ka, and their duration ranges
from 100 to 400 a. The two oldest warm phases coincide with the deposition
of sapropel S1 in the Mediterranean Sea indicating that the climate in the
cave region was influenced by this prominent pluvial phase in the
Mediterranean area. For the younger warm phases it is difficult to establish
a supra-regional climate pattern, and some of them may, thus, reflect
regional climate variability. This highlights the complexity of regional and
supra-regional scale Holocene climate patterns. |
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