HR: 17:15h
AN: B22D-05    [PDF]
TI: Increased Concentrations of Dissolved Organic Carbon During the Spring Floods in the Sagavanirktok, Kuparuk and Colville Rivers in the Alaskan Arctic
AU: * Rember, R D
EM: rrember@fit.edu
AF: Florida Institute of Technology, 150 West University Blvd, Melbourne, FL 32903 United States
AU: Trefry, J H
EM: jtrefry@fit.edu
AF: Florida Institute of Technology, 150 West University Blvd, Melbourne, FL 32903 United States
AB: Arctic rivers discharge 40 to 80% of their annual water volume during the spring floods in May, June and July. During May and June 2001 and 2002, intensive sampling of the Sagavanirktok, Kuparuk and Colville rivers in the Alaskan Arctic was carried out to address questions related to the transport of dissolved and particulate organic carbon to the coastal Beaufort Sea. In June 2001, water flow increased by approximately 250% during peak discharge in the Sagavanirktok River, at the same time concentrations of dissolved organic carbon (DOC) increased from 167 to 742 micromolar. As water flow decreased in the 4 days following peak discharge, concentrations of DOC decreased to $<$300 micromolar. Similar results were found for the Kuparuk and Colville rivers. In May 2002, concentrations of DOC in the Kuparuk River increased from 670 to $>$1140 micromolar in 3 days and decreased with water discharge to 600 micromolar within 6 days of peak water discharge. In the Sagavanirktok River, concentrations of DOC increased from 420 to $>$600 micromolar during the first two days of water discharge in 2002. However, during the next 4 days, temperature dropped to below freezing and surface water flow in the Sagavanirktok River stopped. Consequently, concentrations of DOC decreased to 440 micromolar. However, when water flow resumed, concentrations of DOC increased to $>$850 micromolar before dropping to 200 micromolar within 9 days. Concentrations of particulate organic carbon averaged $>$5% (dry weight) in the Kuparuk River during 2002 and were significantly higher than concentrations found in the Sagavanirktok River (1.6%) during that same period. However, Based on these data, Alaskan Arctic rivers discharge $>$83% and $>$88% of the dissolved and particulate carbon, respectively, during the spring floods. These results suggest that the storage and subsequent flushing of organic carbon from arctic soils during the spring floods is an important component of the flux of organic carbon to the coastal Beaufort Sea.
DE: 1615 Biogeochemical processes (4805)
DE: 1806 Chemistry of fresh water
DE: 1823 Frozen ground
DE: 1890 Wetlands
SC: Biogeosciences [B]
MN: 2003 Fall Meeting