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The strontium and neodymium isotopic signature of aeolian mineral particles archived in polar ice cores provides constraints on the geographic provenance of dust and paleo-atmospheric circulation patterns. Data from different ice cores drilled in the centre of the East Antarctic plateau such as EPICA-Dome C (EDC, 75°06′S; 123°21′E) and Vostok (78°28′S, 106°48′E) suggested a uniform geographic provenance for dust during Pleistocene glacial ages, likely from southern South America (SSA). In this work the existing dust isotopic data from EDC have been integrated with new data from Marine Isotopic Stage (MIS) 14 (about 536 ka before 1950AD) and in parallel some first results are shown for the new TALDICE ice core which was drilled on the edge of the East Antarctic Plateau (Talos Dome, 72°48′S, 159°06′E) on the opposite side with respect to SSA. Interestingly, the isotopic composition of TALDICE glacial dust is remarkably similar to that obtained from glacial dust from sites located in the East Antarctic interior. Overall, the glacial dust isotopic field obtained from six East Antarctic ice cores matches well South American data obtained from target areas. In this respect, it was recently suggested that dust exported long-range from South America originates from Patagonia and from the Puna-Altiplano plateau. To test this hypothesis, we analysed the isotopic composition of dust from an ice core drilled on the Illimani glacier (Bolivia, 16°37′S, 67°46′W; 6350 m a.s.l.) in order to obtain information on the isotopic composition of regional mineral aerosol uplifted from the Altiplano area and likely transported over a long distance. Altogether, ice core and source data strongly suggest that the westerly circulation pattern allowed efficient transfer of dust from South America to the East Antarctic plateau under cold Quaternary climates. Isotopic data support the hypothesis of a possible mixing of dust from Patagonia and from the Puna-Altiplano plateau. Interestingly, high glacial dust inputs to Antarctica are characterized by less radiogenic Nd values, an issue suggesting that enhanced dust production in Patagonia was associated with the activation of a secondary source. Still, Patagonia was the most important supplier for dust to central East Antarctica during Quaternary glaciations. Fil: Delmonte, B.. Università degli Studi di Milano; Italia Fil: Andersson, P. S.. Swedish Museum for Natural History. Laboratory for Isotope Geology; Suecia Fil: Schöberg, H.. Swedish Museum for Natural History. Laboratory for Isotope Geology; Suecia Fil: Hansson, M.. Stockholms Universitet; Suecia Fil: Petit, J. R.. Université Joseph Fourier; Francia Fil: Delmas, R.. Université Joseph Fourier; Francia Fil: Gaiero, Diego Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina Fil: Maggi, V.. Università degli Studi di Milano; Italia Fil: Frezzotti, M.. Laboratory for Climate Observations; Italia

Sedimentary archives at or near the timberline ecotone in Alpine glaciated areas contain records to study Holocene climate change and the interplay between climate, ecosystems, and humans. We focused on records of timberline and glacier oscillations in the Rutor Glacier forefield (Western Italian Alps) in the last 8800 years. Human activity in this area was negligible for most of the Holocene. We adopted an integrative stratigraphic approach including proxies for glacier advance and timberline estimation, sedimentary events, and reconstructed temperatures. Changes in timberline ecotone correlate to climate until the Middle Ages. Pollen-stratigraphic evidence of a primary plant succession highlights a lag beween local deglaciation and the first reliable 14C age. The radiocarbon chronology points to a prolonged phase of glacier contraction between 8.8 and 3.7 ka cal BP. Even later the glacier remained within its LIA limits. Between 8.4 and 4 ka cal BP MAT-inferred TJuly fluctuated near 12.4 °C, ca. 3.1 °C higher than today. During this period, a Pinus cembra forest belt grew at 2600 m asl with an upper limit of tree groves placed 434 ± 310 m above the current open forest limit. This Holocene phase of thermal maximum ended between 3.98 and 3.51 ± 70 ka cal BP and with a substantial rearrangement of forest composition; temperature reconstruction shows a decrease of 1.8 °C. This climate deterioration concluded the Subboreal thermal optimum, mirroring glacial advances widely documented in the Alps. The Rutor Glacier advanced at ca. AD 1093 ± 65, and remained inside the LIA maximum extent. The LIA started since AD 1594, and culminated between AD 1751 and 1864.

During the last glaciation the Eurasian continent was impacted by the global reorganization of atmospheric circulation caused by North Atlantic events, through changes in moisture storm tracks modulated by orography. Our research explores the linkages between climate evolution in the North Atlantic and in the Alps between 30.6 and 12.5 ka, This period, centered on the Last Glacial Maximum, experienced the most recent phase of maximum global ice volume, corresponding to a millennia-long phase of sea-level lowstand, minima in reconstructed sea surface temperatures and isotopic values from polar ice. We present a high-resolution multiproxy record from Lake Fimon at the southern Alpine foothills, where a larch forest-steppe persisted throughout the coldest spells. We analyse the fine climate structure of the MIS 3–2 transition, of the Alpine Last Glacial Maximum stepped by HS2, and provide an unprecedented fine resolution and accurate 14C dating of the Last Glacial Maximum and the early Alpine Lateglacial. We reconstructed quantitative climate parameters based on sensitive pollen descriptors, and derived co-registered sedimentary proxies for dust flux. Reconstructed series suggest that extreme continental spells in the Alps and cold boreal winters match the timing of Heinrich Stadials 2 and 1, episodes of iceberg discharge and release of rock fragments (Ice Rafted Debris) in the North Atlantic. The initiation of the LGM at 27.3 ka is marked by a 4 °C drop in July temperatures, likely responsible for the onset of glacial build-up in the Southern Alpine piedmont. The first extreme continental spell coincides with the British-Irish-sourced IRD event at 26.2 ka and with glacier retreat in the Southern Alps, persisting in the subsequent HS2. Late Glacial glacier collapse and extreme drought occurred during the first half of the HS1, 17.4–16.2 ka. The comparison of the results obtained at Lake Fimon with other terrestrial Eurasian records and with recalibrated marine chronologies from the North Atlantic suggests in-phase reactions of the British-Irish Ice Sheet and of Alpine glaciers and ecosystems to changes in the Atlantic Meridional Circulation. Asymmetric ecoclimatic effects produced by North Atlantic events at the windward and leeward sides of the Alps confirm a southern provenance of moist air masses throughout the LGM.