HR: 17:20h
AN: U44A-05    [Abstracts]
TI: Spatial and Temporal Variability in Active Layer Thickness over the Russian Arctic Drainage Basin
AU: Barry, R G
EM: rbarry@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: * Zhang, T
EM: tzhang@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: Frauenfeld, O W
EM: oliverf@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: Serreze, M
EM: serreze@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: Etringer, A
EM: etringer@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: Oelke, C
EM: coelke@uni-muenster.de
AF: University of Munster, University of Mnster, Institute for Geophysics, Mnster, J-48149 Germany
AU: McCreight, J
EM: mccreigh@nsidc.org
AF: National Snow and Ice Data Center, NSIDC/CIRES, 449 UCB University of Colorado at Boulder, Boulder, CO 80309-0449 United States
AU: Gilichinsky, D
EM: gilichin@online.stack.net
AF: Russian Academy of Sciences, Institute for Physiochemical and Biological Problems in Soil Science Russian Academy of Sciences, Pushchino, 142290 Russian Federation
AU: Yang, D
EM: ffdy@uaf.edu
AF: University of Alaska fairbanks, Water and Environmental Research Center, Fairbanks, AK 99775 United States
AU: Ye, H
EM: hye2@exchange.calstatela.edu
AF: Colifornia State University, Department of Geography and Urban Analysis, Los Angeles, CA 90032 United States
AU: Ling, F
EM: lingf@zqu.edu.cn
AF: Zhaoqing University, Department of Computer Science, Zhaoqing, 526061 China
AU: Chudinova, S
EM: chudinova@isso.psn.ru
AF: Russian Academy of Sciences, Institute for Physiochemical and Biological Problems in Soil Science Russian Academy of Sciences, Pushchino, 142290 Russian Federation
AB: Changes in active layer thickness (ALT) over northern high-latitude permafrost regions have important impacts on the surface energy balance, hydrologic cycle, carbon exchange between the atmosphere and the land surface, plant growth, and ecosystems as a whole. This study examines the 20th century variations of ALT for the Ob, Yenisey, and Lena River basins. ALT is estimated from historical soil temperature measurements from 17 stations (1956-1990, Lena basin only), an annual thawing index based on surface air temperature data (1901-2002), and numerical modeling (1980-2002). The latter two provide spatial fields. Based on the thawing index, the long-term (1961-1990) average ALT is about 1.87 m in the Ob, 1.67 m in the Yenisey, and 1.69 m in the Lena basin. Over the past several decades, ALT over the three basins shows positive trends, but with different magnitudes. Based on the 17 stations, ALT increased about 0.32 m between 1956 and 1990 in the Lena. To the extent that results based on the soil temperatures represent ground "truth", ALT obtained from both the thawing index and numerical modeling is underestimated. It is widely believed that ALT will increase with global warming. However, this hypothesis needs further refinement since ALT responds primarily to summer air temperature while observed warming has occurred mainly in winter and spring. It is also shown that ALT has complex and inconsistent responses to variations in snow cover.
DE: 0702 Permafrost (0475)
DE: 0704 Seasonally frozen ground
DE: 0706 Active layer
DE: 1823 Frozen ground
DE: 1836 Hydrological cycles and budgets (1218, 1655)
SC: Union [U]
MN: Fall Meeting 2005