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Sources and cycling of carbonyl sulfide in the Sargasso Sea
Author(s) -
Cutter Gregory A.,
Cutter Lynda S.,
Filippino Katherine C.
Publication year - 2004
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2004.49.2.0555
Subject(s) - diel vertical migration , cycling , chemistry , environmental chemistry , carbonyl sulfide , dissolved organic carbon , photic zone , dimethylsulfoniopropionate , surface water , geochemical cycle , sulfide , sulfur , organic matter , phytoplankton , oceanography , environmental science , geology , nutrient , organic chemistry , archaeology , environmental engineering , history
The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L −1 , showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L −1 ) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L −1 h −1 , whereas dark production was 7.0 pmol L −1 h −1 . Apparent quantum yields were 10 −5 −10 −7 from 313–436 nm and varied with the water depth irradiated. In March 2000, there were strong diel variations in surface OCS (highest in late afternoon; overall average, 16.9 pmol L −1 ). Depth profiles in the afternoon showed surface water maxima and decreases with depth, whereas DOS had a surface maximum of 419 nmol L −1 and decreased with depth. Dark production was 4.0 pmol L −1 h −1 . Modeling of the diel cycle suggested a photoproduction rate of 16.4 pmol L −1 h −1 . Overall, the photochemical production of OCS strongly depended on DOS and chromophoric dissolved organic matter, whereas dark production was influenced by the presence of particles and perhaps microbial respiration, showing a direct biotic influence on OCS cycling.