scholarly journals Environmental responses of the Northeast Antarctic Peninsula to the Holocene climate variability

2016 ◽  
Vol 31 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Loïc Barbara ◽  
Xavier Crosta ◽  
Amy Leventer ◽  
Sabine Schmidt ◽  
Johan Etourneau ◽  
...  
Keyword(s):  
Climate Variability ◽  
Antarctic Peninsula ◽  
Holocene Climate ◽  
The Holocene ◽  
Environmental Responses

Centennial to millennial-scale variability of Holocene climate and environmental dynamics in the western Mediterranean (Lake Sidi Ali, Middle Atlas, Morocco)

2021 ◽  
Author(s):  
Johannes Schmidt ◽  
Cathleen Kertscher ◽  
Markus Reichert ◽  
Helen Ballasus ◽  
Birgit Schneider ◽  
...  
Keyword(s):  
North Atlantic ◽  
Climate Changes ◽  
Western Mediterranean ◽  
Future Climate ◽  
Holocene Climate ◽  
The Holocene ◽  
The North ◽  
Middle Atlas ◽  
Environmental Responses

<p>The Western Mediterranean region including the North African desert margin is considered one of the most sensitive areas to future climate changes. In order to refine long-term scenarios for hydrological and environmental responses to future climate changes in this region, it is important to improve our knowledge about past environmental responses to climatic variability at centennial to millennial timescales. During the last two decades, the recovery and compilation of Holocene records from the subtropical North Atlantic and the Mediterranean Sea have improved our knowledge about millennial-scale variability of the Western Mediterranean palaeoclimate. The variabilities appear to affect regional precipitation patterns and environmental systems in the Western Mediterranean, but the timescales, magnitudes and forcing mechanisms remain poorly known. To compare the changes in Holocene climate variability and geomorphological processes across temporal scales, we analysed a 19.63-m long sediment record from Lake Sidi Ali (33°03’ N, 5°00’ W, 2080 m a.s.l.) in the sub-humid Middle Atlas that spans the last 12,000 years (23 pollen-based radiocarbon dates accompanied with <sup>210</sup>Pb results). We use calibrated XRF core scanning records with an annual to sub-decadal resolution to disentangle the complex interplay between climate changes and environmental dynamics during the Holocene. Data exploration techniques and time series analysis (Redfit, Wavelet) revealed long-term changes in lake behaviour. Three main proxy groups were identified (temperature proxies: 2ky, 1ky and 0.7ky cycles; sediment dynamic proxies: 3.5ky, 1.5ky cycles; hydrological proxies: 1.5ky, 1.2ky, 0.17ky cycles). For example, redox sensitive elements Fe and Mn show 1ky cycles and higher values in the Early Holocene and 1.5ky cycles and lower values in the Mid- to Late Holocene. All groups show specific periodicities throughout the Holocene, demonstrating their particular climatic and geomorphological dependencies. Furthermore, we discuss these periodicities relating to global and hemispheric drivers, such as the North Atlantic Oscillation (NAO), El-Niño Southern Oscillation (ENSO), Innertropical Convergence Zone variability (ITCZ) and North Atlantic cold relapses (Bond events).</p>

scholarly journals Holocene climate variability in north-eastern Italy: potential influence of the NAO and solar activity recorded by speleothem data

2012 ◽  
Vol 8 (4) ◽  
pp. 1367-1383 ◽  
Author(s):  
D. Scholz ◽  
S. Frisia ◽  
A. Borsato ◽  
C. Spötl ◽  
J. Fohlmeister ◽  
...  
Keyword(s):  
Solar Activity ◽  
Stable Isotope ◽  
Climate Variability ◽  
Regional Climate ◽  
Regional Scale ◽  
Holocene Climate ◽  
Winter Climate ◽  
The Holocene ◽  
North Eastern ◽  
The Mediterranean

Abstract. 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.

scholarly journals Holocene climate variability in North-Eastern Italy: potential influence of the NAO and solar activity recorded by speleothem data

2012 ◽  
Vol 8 (2) ◽  
pp. 909-952 ◽  
Author(s):  
D. Scholz ◽  
S. Frisia ◽  
A. Borsato ◽  
C. Spötl ◽  
J. Fohlmeister ◽  
...  
Keyword(s):  
Solar Activity ◽  
Stable Isotope ◽  
Climate Variability ◽  
Regional Climate ◽  
Regional Scale ◽  
Holocene Climate ◽  
Winter Climate ◽  
The Holocene ◽  
North Eastern ◽  
The Mediterranean

Abstract. 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 show a significant influence of the North Atlantic Oscillation (NAO) on winter 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.

scholarly journals Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history

Nature ◽  
2012 ◽  
Vol 489 (7414) ◽  
pp. 141-144 ◽  
Author(s):  
Robert Mulvaney ◽  
Nerilie J. Abram ◽  
Richard C. A. Hindmarsh ◽  
Carol Arrowsmith ◽  
Louise Fleet ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Ice Shelf ◽  
Holocene Climate
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