Photochemical studies of the Eastern Caribbean: An introductory overview

Journal Article · Mon Feb 15 00:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JC02759· OSTI ID:6721367

Zika, R G; Milne, P J ^[1]; Zafiriou, O C ^[2]

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1. Univ. of Miami, FL (United States)
2. Woods Hole Oceanographic Institution, MA (United States)

This special section of the Journal of Geophysical Research reports a multi-investigator study of a number of sunlight-initiated photoprocesses taking place in the varied biogeochemical and oceanographic environment found in the tropical Eastern Caribbean and Orinoco River delta in the spring and fall of 1988. Principal conceptual themes that were addressed by the program included (1) the characterization of the role of dissolved organic matter as the main chromophore initiating photoprocesses in surface seawater, (2) the determination of the fluxes and pathways of reactants and transient species involved in oxygen photoredox chemistry, and (3) the continuing development of chemical mapping strategies, including observing and modelling reactive phototransient distribution in terms of their sources, mixing, and fates. Ancillary supporting studies included observation of water mass tracers, dissolved trace gases, atmospheric components, nutrients and the geochemistry of estuarine mixing processes in an important continental margin. The observational and mechanistic investigations reported here feature a number of novel or improved methods allied with some advanced underway sampling, sensing and computing facilities that were implemented aboard the R/V Columbus Iselin. Results from the study showed large-scale ([approximately]1,000 km) seasonal variations in surface water photoreactivity, optical and biooptical characteristics over much of the Caribbean basin. These changes resulted from seasonally varying riverine inputs of organic chromophores, nutrients and suspended material. Smaller scale (10-100 km) studies carried out in the Orinoco delta and the Gulf of Paria showed that estuarine mixing processes did not affect major net removal of dissolved organic matter, consistent with the hypothesis that riverine chromophore input plays a dominant role in open-water photochemistry. 56 refs., 4 figs., 1 tab.

• OSTI ID: 6721367
• Journal Information: Journal of Geophysical Research; (United States), Vol. 98:C2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARIBBEAN SEA
PHOTOCHEMISTRY
GASES
SAMPLING
NUTRIENTS
ORGANIC MATTER
BIOGEOCHEMISTRY
CHEMISTRY
CONTINENTAL MARGIN
DISTRIBUTION
ENVIRONMENT
GEOCHEMISTRY
HYPOTHESIS
INVESTIGATIONS
MAPPING
MASS
MIXING
OCEANOGRAPHY
OXYGEN
REDOX REACTIONS
REMOVAL
RIVERS
SEASONAL VARIATIONS
SEAWATER
SEDIMENTS
WATER
ADMINISTRATIVE PROCEDURES
ATLANTIC OCEAN
CHEMICAL REACTIONS
ELEMENTS
FLUIDS
HYDROGEN COMPOUNDS
MATTER
NONMETALS
OXYGEN COMPOUNDS
SEAS
STREAMS
SURFACE WATERS
VARIATIONS
540110*