HR: 1340h
AN: GC23A-0984    [Abstracts]
TI: Changes in Seasonal Snow Cover in Tien Shan During the MODIS Period of Record
AU: Khalsa, S S
EM: sjsk@nsidc.org
AF: National Snow and Ice Data Center, University of Colorado, Boulder, CO 80309-0449, United States
AU: Aizen, V B
EM: aizen@uidaho.edu
AF: Department of Geography, College of Science University of Idaho, McClure 203, Moscow, ID 83844-3021, United States
AU: * Surazakov, A B
EM: asurazakov@vandals.uidaho.edu
AF: Department of Geography, College of Science University of Idaho, McClure 203, Moscow, ID 83844-3021, United States
AU: Aizen, E M
EM: eaizen@uidaho.edu
AF: Department of Geography, College of Science University of Idaho, McClure 203, Moscow, ID 83844-3021, United States
AB: Snow melt in the Tien Shan region accounts for a large portion of the seasonal water supply for millions of inhabitants of central Asia. Studies based on in situ records suggest that maximum snow depth and snow duration in the Tien Shan has decreased, as has annual river flow at lower elevations, over the past 50 years [Aizen et al., 1997]. While the need to monitor trends in winter snow accumulation increase as this resource is threatened by climate change, the number of in situ measurements of snow depth has declined, forcing reliance on remote sensing methods. This talk will describe trends in seasonal snow cover for 8 individual hydrological basins in Central Asia, as well as for the Tien Shan as a whole, using operational products derived from the MODIS Terra instrument. The ultimate goal is to provide input data for snow runoff models. Data from the Moderate-Resolution Imaging Spectroradiometer (MODIS) data, available since early 2000, have proven useful for a large variety of land, ocean and atmospheric applications. The MODIS standard snow-cover products, archived at the National Snow and Ice Data Center, are available in swath-based, daily, 8-day and monthly aggregations at a variety of spatial resolutions and grids. Similar products are also available from the MODIS Aqua instrument launched in 2002. For this study daily and 8-day products at 500m resolution were used. Seven winter seasons were analyzed. For a given season the date of maximum snow coverage varies widely between basins but for the Tien Shan as a whole the period of peak coverage and the rate at which the total snow covered area declines is rather consistent for the 7 winters. Some basins have a large degree of the interannual variability in maximum snow cover while for others this variability is small. Interannual variability in total snow cover for the Tien Shan as a whole is approximately 10 % RMS throughout the peak and decay periods, with 2003 having the most snow cover and 2000 having the least.
DE: 1855 Remote sensing (1640)
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 1895 Instruments and techniques: monitoring
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting