HR: 0800h
AN: OS41A-0460    [Abstracts]
TI: The conservative and non-conservative properties of DOM in the Beaufort Sea
AU: * Osburn, C
EM: cosburn@ccs.nrl.navy.mil
AF: US Naval Research Laboratory, Code 6114 4555 Overlook Ave SW, Washington, DC 20375 United States
AU: Stedmon, C
EM: cst@dmu.dk
AF: National Environmental Research Institute, Department of Marine Ecology, P.O. Box 358, Frederiksborgvej 399, Roskilde, DK-4000 Denmark
AU: Vincent, W
EM: warwick.vincent@bio.ulaval.ca
AF: D‚pt de Biologie, Universit‚ Laval, Pavillon Alexandre-Vachon, Quebec, QC G1K 7P4 Canada
AB: The Beaufort Sea is strongly influenced by the Mackenzie River, which annually discharges large amounts of dissolved organic matter (DOM) to the western Arctic Ocean. We have evidence from water samples collected in 2002 that DOM from the Mackenzie River may be consumed such that DOM behaves non-conservatively up to a salinity of 20 in the Beaufort Sea. Experimental evidence showed that Mackenzie River DOM is highly susceptible to photochemical degradation and we have calculated rates of DOM oxidation and photobleaching. These rates provide upper estimates on the turnover of terrigenous organic carbon in the Beaufort Sea. A possible mechanism is presented that suggests residence time in the surface waters of the Beaufort Gyre as the mechanism by which Mackenzie River DOM may be removed.
DE: 4806 Carbon cycling
DE: 4847 Optics
DE: 4852 Photochemistry
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting