HR: 1340h
AN: PP23A-1082    [Abstracts]
TI: Aeolian dust dynamics in Central Asia during the Pleistocene: driven by alternating atmospheric circulation patterns and/or the seasonal shift of the Asiatic polar front
AU: * Machalett, B
EM: b.machalett@nakula.de
AF: Department of Geology, University of South Florida, 4202 Fowler Ave. SCA528, Tampa, FL 33620, United States
AU: * Machalett, B
EM: b.machalett@nakula.de
AF: Leibniz Institute for Applied Geosciences (GGA-Institut), S3 :Geochronology and Isotope Hydrology, Stilleweg 2, Hannover, 30655, Germany
AU: * Machalett, B
EM: b.machalett@nakula.de
AF: Chair of Geomorphology, University of Bayreuth, Universitaetsstr. 30, Bayreuth, 95440, Germany
AU: Oches, E A
EM: oches@cas.usf.edu
AF: Department of Geology, University of South Florida, 4202 Fowler Ave. SCA528, Tampa, FL 33620, United States
AU: Frechen, M
EM: M.Frechen@gga-hannover.de
AF: Leibniz Institute for Applied Geosciences (GGA-Institut), S3 :Geochronology and Isotope Hydrology, Stilleweg 2, Hannover, 30655, Germany
AU: Zoeller, L
EM: ludwig.zoeller@uni-bayreuth.de
AF: Chair of Geomorphology, University of Bayreuth, Universitaetsstr. 30, Bayreuth, 95440, Germany
AU: Mavlyanova, N
EM: mavnad13@rambler.ru
AF: G.A. Mavlyanov Institute of Seismology, Uzbek Academy of Sciences, 3, Khurshid str, C-12, Tashkent, 700128, Uzbekistan
AU: Markovic, S B
EM: zbir@im.ns.ac.yu
AF: Quaternary Research Centre, Department of Geography, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Yugoslavia
AU: Hambach, U
EM: ulrich.hambach@uni-bayreuth.de
AF: Chair of Geomorphology, University of Bayreuth, Universitaetsstr. 30, Bayreuth, 95440, Germany
AU: Endlicher, W
EM: wilfried.endlicher@geo.hu-berlin.de
AF: Humboldt-University of Berlin, Department of Geography, Chair of Climatology and Vegetation Geography, Unter den Linden 6, Berlin, 10099, Germany
AB: Loess-palaeosol sequences preserve detailed archives of climate change, reflecting the dynamics of aeolian dust sedimentation and the palaeo-dust content of the atmosphere. The detailed investigation of particle size distributions of windblown sediments is an increasingly used approach to assess the palaeorecord of aeolian dust dynamics. The Central Asian loess belt offers the potential to carry out granulometric studies and to reconstruct Pleistocene atmospheric circulation patterns in Eurasia. In this study we present the aeolian dust record of the loess sequence at Remisowka (Almaty, SE Kazakhstan), which reflects a detailed signal of glacial-interglacial dynamics in Central Asia. Based on radiocarbon and amino acid geochronologic data, long-term semi- continuous trends in the aeolian dust record of the Last Glacial Cycle are measured in order to interpret their palaeoclimate signal. In consideration of the modern synoptical atmospheric circulation patterns and aeolian dust transport in Central Asia, it is likely that the observed trends reflect a long term signal of seasonality, triggered by changes in duration and permanency of the seasonal shift of the Asiatic polar front during the middle to late Pleistocene. Previously published models, which focused on the glacial-interglacial reciprocity of the zonal Westerlies and Asiatic high in Central Asia, were overly simplified and should be modified to include the influence of the Asiatic polar front. As the position of the high level planetary frontal zone mainly affects the development and seasonal shift of the Asiatic polar front, it is likely that an inter-hemispheric mechanism exists, that links dust deposition between Europe and Central Asia.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1637 Regional climate change
DE: 4914 Continental climate records
DE: 4928 Global climate models (1626, 3337)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting