HR: 0800h
AN: A51B-0039    [Abstracts]
TI: Observations of Dissolved CO and Chromatophoric Dissolved Organic Matter in Coastal Ocean Waters in Northern California
AU: * Day, D A
EM: daday@ucdavis.edu
AF: Univsersity of California at Davis, LAWR Dept. 1 Shields Ave., Davis, CA 95616 United States
AU: Faloona, I C
EM: icfaloona@ucdavis.edu
AF: Univsersity of California at Davis, LAWR Dept. 1 Shields Ave., Davis, CA 95616 United States
AB: Dissolved carbon monoxide (CO(aq)) has been shown to be ubiquitously supersaturated in the surface ocean due its in situ production resulting from the photolysis of chromatophoric dissolved organic matter (CDOM). We present observations of CO(aq) and CDOM in the surface coastal waters in Northern California made during spring/summer 2005. Rates of microbial bio-oxidation of CO(aq) were also measured following some sampling periods and atmospheric CO observations spanned the entire duration of the intensive seawater sampling periods. In addition, supporting measurements of temperature, salinity, turbidity, and fluorescence of surface seawater values were recorded. The sampling was conducted periodically along a transect from 1 to 20 km perpendicular to the coastline at Bodega Marine Laboratory located approximately 60 km northwest of San Francisco. During the summer months, the Northern California coastal ocean experiences intense upwelling bringing deep ocean water to the surface enriching the euphotic zone with high nutrient concentrations, contributing to the high primary productivity of this region and thus potentially very different and more rapidly cycling environment compared to the open ocean for which most CO(aq) observations have been reported. Our observations show both enhanced CO(aq) concentrations and bio-oxidation rates compared to open ocean waters values. Collectively, these observations allow for quantitative constraints of the CO air-sea gas exchange and surface seawater CO(aq) cycling including loss by microbial bio-oxidation and production by both CDOM photolysis and "dark production" in this coastal region.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0428 Carbon cycling (4806)
DE: 0442 Estuarine and nearshore processes (4235)
DE: 0490 Trace gases
DE: 4217 Coastal processes
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005