title: CDOM Sources and Photobleaching Control Quantum Yields for Oceanic DMS Photolysis.
abstract: Photolysis is a major removal pathway for the biogenic gas dimethylsulfide (DMS) in the surface ocean. Here we tested the hypothesis that apparent quantum yields (AQY) for DMS photolysis varied according to the quantity and quality of its photosensitizers, chiefly chromophoric dissolved organic matter (CDOM) and nitrate. AQY compiled from the literature and unpublished studies ranged across 3 orders of magnitude at the 330 nm reference wavelength. The smallest AQY(330) were observed in coastal waters receiving major riverine inputs of terrestrial CDOM (0.06-0.5 m3(mol quanta)-1). In open-ocean waters, AQY(330) generally ranged between 1 and 10 m3(mol quanta)-1. The largest AQY(330), up to 34 m3(mol quanta)-1), were seen in the Southern Ocean potentially associated with upwelling. Despite the large AQY variability, daily photolysis rate constants at the sea surface spanned a smaller range (0.04-3.7 d-1), mainly because of the inverse relationship between CDOM absorption and AQY. Comparison of AQY(330) with CDOM spectral signatures suggests there is an interplay between CDOM origin (terrestrial versus marine) and photobleaching that controls variations in AQYs, with a secondary role for nitrate. Our results can be used for regional or large-scale assessment of DMS photolysis rates in future studies.
authors.affiliation: Takuvik Joint International Laboratory (Université Laval - CNRS), Biology Department, Université Laval , 1045 Avenue de la Médecine, G1 V 0A6 Québec, Quebec, Canada.
authors.forename: Martí
authors.identifier: 0000-0002-5587-1271
authors.initials: M
authors.lastname: Galí
authors.affiliation: Department of Chemistry, College of Environmental Science and Forestry, State University of New York , 1 Forestry Drive, Syracuse, New York 13210, United States.
authors.forename: David J
authors.identifier: 0000-0001-6532-950X
authors.initials: DJ
authors.lastname: Kieber
authors.affiliation: Rosenstiel School of Marine and Atmospheric Science, RSMAS/OCE, University of Miami , Miami, Florida 33149, United States.|Department of Limnology and Bio-Oceanography, Center of Ecology, University of Vienna , 1090 Vienna, Austria.
authors.forename: Cristina
authors.initials: C
authors.lastname: Romera-Castillo
authors.affiliation: Department of Chemistry, College of Environmental Science and Forestry, State University of New York , 1 Forestry Drive, Syracuse, New York 13210, United States.|Department of Marine, Earth and Atmospheric Sciences, North Carolina State University , 2800 Faucette Drive, Raleigh, North Carolina 27695, United States.
authors.forename: Joanna D
authors.initials: JD
authors.lastname: Kinsey
authors.affiliation: Takuvik Joint International Laboratory (Université Laval - CNRS), Biology Department, Université Laval , 1045 Avenue de la Médecine, G1 V 0A6 Québec, Quebec, Canada.|Fisheries and Oceans Canada, Bedford Institute of Oceanography , Dartmouth, NS B2Y 4A2, Canada.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Devred
authors.affiliation: Instituto INIBIOMA (CRUB Comahue, CONICET), Quintral 1250, 8400 S.C. de Bariloche, Rio Negro, Argentina.
authors.forename: Gonzalo L
authors.initials: GL
authors.lastname: Pérez
authors.affiliation: Department of Chemistry, College of Environmental Science and Forestry, State University of New York , 1 Forestry Drive, Syracuse, New York 13210, United States.
authors.forename: George R
authors.initials: GR
authors.lastname: Westby
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC) , Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Catalonia Spain.
authors.forename: Cèlia
authors.initials: C
authors.lastname: Marrasé
authors.affiliation: Takuvik Joint International Laboratory (Université Laval - CNRS), Biology Department, Université Laval , 1045 Avenue de la Médecine, G1 V 0A6 Québec, Quebec, Canada.
authors.forename: Marcel
authors.initials: M
authors.lastname: Babin
authors.affiliation: Takuvik Joint International Laboratory (Université Laval - CNRS), Biology Department, Université Laval , 1045 Avenue de la Médecine, G1 V 0A6 Québec, Quebec, Canada.
authors.forename: Maurice
authors.initials: M
authors.lastname: Levasseur
authors.affiliation: King Abdullah University of Science and Technology (KAUST) , Red Sea Research Center (RSRC), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Duarte
authors.affiliation: King Abdullah University of Science and Technology (KAUST) , Red Sea Research Center (RSRC), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Susana
authors.initials: S
authors.lastname: Agustí
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC) , Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Catalonia Spain.
authors.forename: Rafel
authors.initials: R
authors.lastname: Simó
mesh_terms: D009566:Nitrates; D009792:Oceans and Seas; D038761:Photobleaching; D010782:Photolysis
chemical_list: D009566:Nitrates