Aquatic Sciences Meeting, Albuquerque 2001

SS02 Photochemical Reactions In Surface Waters: A Major Issue in the 21st Century? (Environmental Connections)

Date: Friday, February 16, 2001, Time: 8:30:00 AM

Location: San Miguel

Siegel, D, A, ICESS, UC Santa Barbara, Santa Barbara, CA, USA, davey@icess.ucsb.edu

GLOBAL DISTRIBUTION AND DYNAMICS OF CHROMOPHORIC DISSOLVED ORGANIC MATTER: IMPLICATIONS FOR MARINE PHOTOCHEMISTRY

Chromophoric dissolved organic matter (CDOM) is the intermediary for many photochemical reactions that regulate upper ocean elemental cycling and the air-sea exchange of important trace gases. However, its time-space distribution, sources and sinks, relationship to the dissolved organic carbon (DOC) pool and influence on ocean light availability and photochemical reaction rates remain largely in question. Satellite imagery from the Sea-viewing Wide Field-of-view Sensor mission and recent advances in ocean color algorithms are used to characterize the global distribution of total colored organic materials (TCOM). TCOM represents the combined influence of CDOM and detrital particulates on light absorption and a global synthesis of field observations indicates that CDOM dominates the TCOM signal. Basin scale TCOM patterns resemble phytoplankton pigment distributions to first order, TCOM concentrations are not directly related to DOC and TCOM comprises ~63% of the non-water blue light absorption. Signature from river discharges can be discerned although their effects are localized. Preliminary calculations of the global distribution of the CO photoproduction rate are presented.

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Aquatic Sciences Meeting, Albuquerque 2001

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