HR: 0800h
AN: U41A-0814    [Abstracts]
TI: A Pan-Arctic Evaluation of Changes in River Discharge During the Latter Half of the 20th Century
AU: * McClelland, J
EM: jmcclelland@mbl.edu
AF: Marine Biological Laboratory, The Ecosystems Center, Woods Hole, MA 02543 United States
AU: Déry, S
EM: sdery@unbc.ca
AF: University of Northern BC, Environmental Science and Engineering Program, Prince George, BC V2N 4Z9 Canada
AU: Peterson, B
EM: peterson@mbl.edu
AF: Marine Biological Laboratory, The Ecosystems Center, Woods Hole, MA 02543 United States
AU: Holmes, R
EM: rmholmes@whrc.org
AF: The Woods Hole Research Center, PO Box 296, Woods Hole, MA 02543
AU: Wood, E
EM: efwood@princeton.edu
AF: Princeton University, Dept. Civil and Environmental Engineering, Princeton, NJ 08544 United States
AB: Several recent publications have documented regional changes in river discharge from arctic and subarctic watersheds. Most notably, increases in discharge were identified in Eurasia and decreases in discharge were identified in North America. Comparison of these findings, however, has been hampered by differences in the time periods and analytical methods used in the various studies. In this presentation we will compare changes in river discharge from different regions of the pan-arctic watershed (Arctic Ocean watershed plus the Hudson, James, and Ungava Bay watersheds) using identical time periods (1964-2000) and analytical methods. Preliminary calculations show that discharge to the Arctic Ocean from Eurasia increased by about 6.1 km³/y/y during the 1964-2000 period (slope of Kendall-Theil Robust Line), whereas discharge to the Arctic Ocean from North America decreased by 0.6 km³/y/y during the 1964-2000 period. The net effect of these changes is that the Arctic Ocean experienced a 5.5 km³/y/y increase in freshwater inputs from rivers during the 1964-2000 period amounting to 205 km³/y greater discharge at the end of the time period as compared to the beginning. In contrast to the overall increases in river discharge to the Arctic Ocean, discharge to Hudson, James, and Ungava Bays decreased by about 2.5 km³/y/y during the 1964-2000 period amounting to 92 km³/y less discharge at the end of the time period as compared to the beginning. Overall, this evaluation indicates that there has been a net increase in river discharge from the pan-arctic watershed (112 km³/y greater discharge at the end of the time period as compared with the beginning for all regions combined). More importantly, however, this evaluation highlights the need to understand the consequences of adding or removing freshwater (via rivers or any other freshwater source) from particular regions of the Arctic and Subarctic oceans. For example, what is the fate of water flowing from the Hudson, James and Ungava Bays? To what degree may decreases in freshwater from the Hudson region offset increases in freshwater from the Arctic Ocean at critical deep-water formation areas of the Labrador and Nordic Seas?
DE: 1630 Impacts of global change (1225)
DE: 1637 Regional climate change
DE: 1655 Water cycles (1836)
DE: 1836 Hydrological cycles and budgets (1218, 1655)
SC: Union [U]
MN: Fall Meeting 2005