HR: 0800h
AN: U41A-0807    [Abstracts]
TI: A Statistical Analysis of Precipitation and River Discharge Variability in the Eurasian Arctic
AU: * Pavelsky, T M
EM: pavelsky@ucla.edu
AF: UCLA Department of Geography, 1255 Bunche Hall Box 951524, Los Angeles, CA 90095 United States
AU: Smith, L C
EM: lsmith@geog.ucla.edu
AF: UCLA Department of Geography, 1255 Bunche Hall Box 951524, Los Angeles, CA 90095 United States
AU: Sampson, K
EM: ksampson@gmail.com
AF: University of Colorado Department of Geography, 260 UCB, Boulder, CO 80309 United States
AU: Lammers, R
EM: Richard.Lammers@unh.edu
AF: Waters Systems Analysis Group, Morse Hall, Room 211 University of New Hampshire, Durham, NH 03824 United States
AU: Shiklomanov, A
EM: Alexander.Shiklomanov@unh.edu
AF: Waters Systems Analysis Group, Morse Hall, Room 211 University of New Hampshire, Durham, NH 03824 United States
AU: MacDonald, G
EM: macdonal@geog.ucla.edu
AF: UCLA Department of Geography, 1255 Bunche Hall Box 951524, Los Angeles, CA 90095 United States
AB: The importance of Arctic river systems to regional and global environments has been well documented. Recently observed increases in freshwater discharge may influence Arctic Ocean ice pack dynamics and, by extension, have a substantial impact on thermohaline circulation and global climate. Despite its critical role as both a driver and an indicator of climate change, however, many aspects of the Arctic hydrologic cycle are poorly understood. In particular, we aim to better understand the forces influencing observed river discharge increases from Arctic Eurasia since the 1930s. Past studies have examined increased fire frequency, permafrost melting, and dam construction as possible mechanisms. Here, we focus on precipitation as the most likely driver of discharge change. We compare river-year precipitation and discharge data for a set of 245 river basins in Arctic Eurasia, utilizing discharge data from the R-ArcticNet 3.0 database and a variety of precipitation datasets including interpolated data from the University of Delaware (Udel) and the University of Washington (UW) and reanalysis data from NCEP/NCAR and ECMWF (ERA-40). Correlations between annual precipitation and discharge values over the period 1958-1989, during which all of the datasets overlap, suggest that the interpolated data significantly outperform both reanalysis datasets. Because of its long duration (1930-1998) and minimal differences with the UW data for these purposes, the Udel dataset is used to explore a possible link between precipitation and discharge changes over the period 1936-1999. Statistical comparisons of trends in precipitation and discharge over this timeframe suggest that precipitation change, while perhaps not the sole mechanism, plays a significant role in observed discharge increases. Further analysis comparing discharge changes with permafrost extent indicate that permafrost melt probably plays little, if any, role in discharge variability.
DE: 0744 Rivers (0483, 1856)
DE: 1833 Hydroclimatology
DE: 1854 Precipitation (3354)
DE: 1876 Water budgets
DE: 9315 Arctic region (0718, 4207)
SC: Union [U]
MN: Fall Meeting 2005