HR: 17:15h
AN: C44A-06    [Abstracts]
TI: Central Asian Water Cycle Variability over the past Century from Ice-core Isotope Records (Altai, Tien Shan)
AU: * Aizen, V
EM: aizen@uidaho.edu
AF: Department of Geography, University of Idaho, College of Science, Mines Bld., Box 443025, Moscow, ID 83844-3025 United States
AU: Aizen, E
EM: eaizen@uidaho.edu
AF: Department of Geography, University of Idaho, College of Science, Mines Bld., Box 443025, Moscow, ID 83844-3025 United States
AU: Mayewski, P
EM: paul.mayewski@maine.edu
AF: Climate Change Institute, University of Maine, Bryand Global Sciences Center, Orono, ME 04469-5790 United States
AU: Kreutz, K
EM: karl.kreutz@maine.edu
AF: Climate Change Institute, University of Maine, Bryand Global Sciences Center, Orono, ME 04469-5790 United States
AU: Joswiak, D
EM: josw4889@uidaho.edu
AF: Department of Geography, University of Idaho, College of Science, Mines Bld., Box 443025, Moscow, ID 83844-3025 United States
AU: Takeuchi, N
EM: takeuchi@chikyu.ac.jp
AF: Research Institute for Humanity and Nature, 335 Takashima-cho, Kamigyo-ku, Kyoto, 602-0878 Japan
AU: Fujita, K
EM: cozy@ihas.nagoya-u.ac.jp
AF: Nagoya University, Graduate School of Environmental Studies, c/o Hydrospherc Atmospheric Research Center, Chikusa-ku , Nagoya, 464-8601 Japan
AB: The Altai and Tien Shan ice cores records are expanding our understanding of the inter-Hemispheric water cycle and climate dynamics: the moisture advection from Atlantic and Pacific Oceans, and from Aral-Caspian closed drainage basin to the Arctic Ocean defining the interaction over time between the westerly jet stream, and the Asian monsoon, Siberian and Tibetan Highs and deciphering local verses regional change over the temperate and high latitudes. The multi-parameter high-resolution (i.e., sub-seasonal) glacio-climatic and environmental records from the upper fifty meter of the 175 m surface to bottom ice core recovered in 2003 from the Belukha snow-firn plateau at 4115 m (Altai Mts.) and the upper 20 m of the 160 m deep ice-core recovered in 2000 from the head of Inylchek Glacier at 5200 m (Tien Shan Mts.) were developed and evaluated. The long-term meteorological, synoptic, dust storm and forest fire records and physical stratigraphy data were the basis for calibration, validation and interpretation. The mean annual snow accumulation on the Inylchek glacier for the period from 1992 to 1998 was found to be 116 g cm$^{-2}$/yr. Validation of the Altai ice core records through the marker horizon of volcanic eruptions showed monthly accordance in the dating century accumulation ice core records with the mean accumulation rate of 650 g cm$^{-2}$/yr. The $\delta$$^{18}$O, $\delta$D and d excess records showed well-preserved seasonal variation, which is significantly controlled by air temperature, by share of cold/or warm season precipitation amount and origin, transport and recycling of moisture. The $\delta$$^{18}$O-$\delta$D relationship in the upper 50 m of the Altai ice core records has the same slope to the co-variance as that of the global meteoric water line (i.e., 8), while the Tien Shan ice-core records has lower slope (i.e., 7). The snow accumulation of central Asian glaciers was formed from oceanic precipitation and the moisture originated over Aral-Caspian sources. The Northern Atlantic contributed 15% of moisture, while Black and Eastern Mediterranean Seas 32% to the 20 m Inylchek accumulation. The rest precipitation on the Tien Shan glacier has inter-continental origin. The d-excess show means maximum in winter and minimum in summer in both ice-cores records. About 70% of the Altai snow firn core d-excess records vary within 6% and 15% with maximum of more than 40% within the range from 8% to 13% with the shift to higher values in the upper part of ice core pointing on increased share of moisture recycled over intercontinental Asia. More than half of accumulation on the Altai records had Atlantic Ocean origin. Precipitation from the Arctic and Pacific Oceans had the smallest deuterium excess and their share in total accumulation is increasing. Ice core analysis of the composition of $\delta$$^{18}$O reflected different synoptic situations, which will be reconstructed along with air temperature for about the century of ice core records.
UR: http://www.uidaho.edu/~aizen
DE: 3309 Climatology (1620)
DE: 1655 Water cycles (1836)
DE: 1827 Glaciology (1863)
DE: 1040 Isotopic composition/chemistry
DE: 1620 Climate dynamics (3309)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting