HR: 09:00h
AN: GC21B-04    [Abstracts]
TI: Atmosphere aerosol/dust composition over central Asia and western Siberia derived from snow/ice core records and calibrated with NASA remote sensing data
AU: * Aizen, V B
EM: aizen@uidaho.edu
AF: University of Idaho, College of Science, Mines Building, Moscow, ID 83844-3025, United States
AU: Aizen, E M
EM: eaizen@uidaho.edu
AF: University of Idaho, College of Science, Mines Building, Moscow, ID 83844-3025, United States
AU: Joswiak, D R
EM: djoswiak@vandals.uidaho.edu
AF: University of Idaho, College of Science, Mines Building, Moscow, ID 83844-3025, United States
AU: Surazakov, A B
EM: asurazakov@vandals.uidaho.edu
AF: University of Idaho, College of Science, Mines Building, Moscow, ID 83844-3025, United States
AU: Takeuchi, N
EM: ntakeuch@faculty.chiba-u.jp
AF: Chiba University Graduate School of Science and Technology, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
AB: The vast arid and semi-arid regions of central Asia, Mongolia, and Northern China are the world's second largest source of atmospheric mineral dust. In recent years, severe dust storms in Asia have intensified in frequency, duration, and areal coverage. However, limited spatial and temporal extent of aerosol measurements precludes definitive statements to be made regarding relationship between the Asian aerosol generation and climate. It has been well known that glaciers are the natural archives of environmental records related to past climate and aerosol generation. In our research, we utilized central Asian and western Siberia shallow ice-core records recovered from Altai, Tien Shan and Pamir mountain glaciers. Despite the fact that ice-core data may extend climate/aerosol records back in time, their sparse coverage is inadequate to document aerosol spatial distribution. The NASA products from Aura, Terra and Aqua satellite missions address this gap identifying aerosol sources, transport pathways, and area of deposition. The main objective of our research is to evaluate an affect of climate variability on dynamics of Asian aerosol loading to atmosphere and changes in aerosol transport pathways. Dust particle, major and rare earth element analysis from dust aerosols deposited and accumulated in Altai, Tien Shan and Pamir glaciers suggests that loess from Tajikistan, Afghanistan and north-western China are main sources of aerosol loading into the upper troposphere over the central Asia and western Siberia. At the same time, the soluble ionic component of the ice-cores, related to aerosol generated from evaporate deposits, demonstrated both anthropogenic and natural impacts on atmospheric chemistry over these regions. Large perturbations of Ca2+ derived from CaCO3- rich dust transported from Goby Desert to Altai and Tien Shan. Origin and pathway of the ice-core aerosol depositions for the last 10-years were identified through calibrating ice-core records with dust storm land surface records and remote sensing aerosol data at the monthly/seasonal/annual to event/daily scale. For instance, in southwestern Asia, severe drought developed from 1998 to 2002 has intensified the frequency, duration, and spatial coverage of large dust storms originated in Iran, Afghanistan, Tajikistan, Taklimakan and Goby Deserts. The Pamir and Tien Shan ice-core records revealed, that concentration of major and REE elements during summer is about two times greater in period of 1998-2002 than at the following years. Our qualitative analysis based on ice-core records, the MODIS and SeaWiFS images and determined the origin of dust, transport pathways and aerosol spatial distribution over central Asia and western Siberia in summer 2000, 2001 and 2002. The transport pathways were reconstructed on the basis of visibility observations and NCAR MM5-predicted winds with further validation against of satellite data and isotope- geochemical ice-core data analysis.
UR: http://www.sci.uidaho.edu/cae
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0429 Climate dynamics (1620)
DE: 0454 Isotopic composition and chemistry (1041, 4870)
DE: 0480 Remote sensing
DE: 0776 Glaciology (1621, 1827, 1863)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting