TY  - JOUR
A1  - Deplazes, Gaudenz
A1  - Lueckge, Andreas
A1  - Peterson, Larry C.
A1  - Timmermann, Axel
A1  - Hamann, Yvonne
A1  - Hughen, Konrad A.
A1  - Roehl, Ursula
A1  - Laj, Carlo
A1  - Cane, Mark A.
A1  - Sigman, Daniel M.
A1  - Haug, Gerald H.
T1  - Links between tropical rainfall and North Atlantic climate during the last glacial period
JF  - Nature geoscience
N2  - During the last glacial period, the North Atlantic region experienced pronounced, millennial-scale alternations between cold, stadial conditions and milder interstadial conditions-commonly referred to as Dansgaard-Oeschger oscillations-as well as periods of massive iceberg discharge known as Heinrich events(1). Changes in Northern Hemisphere temperature, as recorded in Greenland(2-4), are thought to have affected the location of the Atlantic intertropical convergence zone(5,6) and the strength of the Indian summer monsoon(7,8). Here we use high-resolution records of sediment colour-a measure of terrigenous versus biogenic content-from the Cariaco Basin off the coast of Venezuela and the Arabian Sea to assess teleconnections with the North Atlantic climate system during the last glacial period. The Cariaco record indicates that the intertropical convergence zone migrated seasonally over the site during mild stadial conditions, but was permanently displaced south of the basin during peak stadials and Heinrich events. In the Arabian Sea, we find evidence of a weak Indian summer monsoon during the stadial events. The tropical records show a more variable response to North Atlantic cooling than the Greenland temperature records. We therefore suggest that Greenland climate is especially sensitive to variations in the North Atlantic system-in particular sea-ice extent-whereas the intertropical convergence zone and Indian monsoon system respond primarily to variations in mean Northern Hemisphere temperature.
Y1  - 2013
U6  - https://doi.org/10.1038/ngeo1712
SN  - 1752-0894
VL  - 6
IS  - 3
SP  - 213
EP  - 217
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Calo, Camilla
A1  - Henne, Paul D.
A1  - Eugster, Patricia
A1  - van Leeuwen, Jacqueline
A1  - Gilli, Adrian
A1  - Hamann, Yvonne
A1  - La Mantia, Tommaso
A1  - Pasta, Salvatore
A1  - Vescovi, Elisa
A1  - Tinner, Willy
T1  - 1200 years of decadal-scale variability of mediterranean vegetation and climate at Pantelleria Island, Italy
JF  - The Holocene : an interdisciplinary journal focusing on recent environmental change
N2  - A new sedimentary sequence from Lago di Venere on Pantelleria Island, located in the Strait of Sicily between Tunisia and Sicily was recovered. The lake is located in the coastal infra-Mediterranean vegetation belt at 2 m a.s.l. Pollen, charcoal and sedimentological analyses are used to explore linkages among vegetation, fire and climate at a decadal scale over the past 1200 years. A dry period from ad 800 to 1000 that corresponds to the Medieval Warm Period' (WMP) is inferred from sedimentological analysis. The high content of carbonate recorded in this period suggests a dry phase, when the ratio of evaporation/precipitation was high. During this period the island was dominated by thermophilous and drought-tolerant taxa, such as Quercus ilex, Olea, Pistacia and Juniperus. A marked shift in the sediment properties is recorded at ad 1000, when carbonate content became very low suggesting wetter conditions until ad 1850-1900. Broadly, this period coincides with the Little Ice Age' (LIA), which was characterized by wetter and colder conditions in Europe. During this time rather mesic conifers (i.e. Pinus pinaster), shrubs and herbs (e.g. Erica arborea and Selaginella denticulata) expanded, whereas more drought-adapted species (e.g. Q. ilex) declined. Charcoal data suggest enhanced fire activity during the LIA probably as a consequence of anthropogenic burning and/or more flammable fuel (e.g. resinous Pinus biomass). The last century was characterized by a shift to high carbonate content, indicating a change towards drier conditions, and re-expansion of Q. ilex and Olea. The post-LIA warming is in agreement with historical documents and meteorological time series. Vegetation dynamics were co-determined by agricultural activities on the island. Anthropogenic indicators (e.g. Cerealia-type, Sporormiella) reveal the importance of crops and grazing on the island. Our pollen data suggest that extensive logging caused the local extinction of deciduous Quercus pubescens around ad1750.
KW  - central Mediterranean
KW  - fire history
KW  - "Little Ice Age' (LIA)
KW  - "Medieval Warm Period' (MWP)
KW  - Pinus pinaster
KW  - Quercus ilex
KW  - Quercus pubescens
KW  - vegetation history
Y1  - 2013
U6  - https://doi.org/10.1177/0959683613493935
SN  - 0959-6836
SN  - 1477-0911
VL  - 23
IS  - 10
SP  - 1477
EP  - 1486
PB  - Sage Publ.
CY  - London
ER  -