HR: 13:40h
AN: U33B-01    [Abstracts]
TI: A New Look at the Arctic Freshwater Cycle: The Charge of the Budgeteers
AU: * Serreze, M C
EM: serreze@kryos.colorado.edu
AF: CIRES/NSIDC, Campus Box 449, University of Colorado, Boulder, CO 80309-0449 United States
AB: The Budgeteers, a working group within the NSF-ARCSS Freshwater Initiative, seeks to quantify and link the major terms of the large-scale freshwater cycle of the Arctic. Working group members and contributing colleagues from the University of Colorado (M. Serreze, A. Barrett, A. Slater), the University of Washington (R. Woodgate, K. Aagaard, M. Steele, R. Moritz, C. Lee), the University of New Hampshire (R. Lammers, C. Vorosmarty) and the British Antarctic Survey (M. Meredith) bring varied expertise in the atmospheric, oceanic and land surface components of the Arctic system. We draw from recent oceanographic observations, land surface and hydrologic models, and results from the ECMWF ERA-40 reanalysis. Despite large uncertainties in some of the terms, particularly the oceanic fluxes of liquid water through Fram Strait and the complex channels of the Canadian Arctic Archipelago (for which data are very limited), the mean annual freshwater budget of the combined atmosphere, land and ocean system is reasonably well closed. Outputs exceed inputs by 791 cubic km. However, this imbalance is only about 10 percent of the estimated annual freshwater input to the Arctic Ocean which is driven primarily by river runoff, precipitation less evapo-transpiration (P-ET) over the Arctic Ocean, and the flow of low-salinity waters into the Arctic Ocean through Bering Strait. Terms for which records are sufficient for more focused analysis show strong seasonal and interannual variability. Seasonality in combined runoff, P-ET over the Arctic Ocean, Bering Strait inflow and the Fram Strait ice flux contribute, along with variations in sea ice, to a spring to summer increase in oceanic freshwater storage. The Fram Strait ice outflow shows the largest interannual variability. We estimate a mean residence time of freshwater in the Arctic Ocean of approximately nine years, contrasting sharply with the atmosphere, with a residence time of about seven days.
DE: 0750 Sea ice (4540)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 1655 Water cycles (1836)
DE: 1833 Hydroclimatology
SC: Union [U]
MN: Fall Meeting 2005