title: Photosensitized production of functionalized and unsaturated organic compounds at the air-sea interface.
abstract: The sea-surface microlayer (SML) has different physical, chemical and biological properties compared to the subsurface water, with an enrichment of organic matter i.e., dissolved organic matter including UV absorbing humic substances, fatty acids and many others. Here we present experimental evidence that dissolved organic matter, such as humic acids, when exposed to sunlight, can photosensitize the chemical conversion of linear saturated fatty acids at the air-water interface into unsaturated functionalized gas phase products (i.e. saturated and unsaturated aldehydes and acids, alkenes and dienes,...) which are known precursors of secondary organic aerosols. These functionalized molecules have previously been thought to be of biological origin, but here we demonstrate that abiotic interfacial photochemistry has the potential to produce such molecules. As the ocean is widely covered by the SML, this new understanding will impact on our ability to describe atmospheric chemistry in the marine environment.
authors.affiliation: 1] Université de Lyon 1, Lyon, F-69626, France; CNRS, UMR5256, IRCELYON, Institut de Recherches sur la Catalyse et l'Environnement de Lyon, Villeurbanne, F-69626, France [2].
authors.forename: Raluca
authors.initials: R
authors.lastname: Ciuraru
authors.affiliation: Université de Lyon 1, Lyon, F-69626, France; CNRS, UMR5256, IRCELYON, Institut de Recherches sur la Catalyse et l'Environnement de Lyon, Villeurbanne, F-69626, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Fine
authors.affiliation: Leibniz-Institut für Troposphärenforschung e.V. (TROPOS), Atmospheric Chemistry Dept. (ACD), Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: van Pinxteren
authors.affiliation: Université de Lyon 1, Lyon, F-69626, France; CNRS, UMR5256, IRCELYON, Institut de Recherches sur la Catalyse et l'Environnement de Lyon, Villeurbanne, F-69626, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: D'Anna
authors.affiliation: Leibniz-Institut für Troposphärenforschung e.V. (TROPOS), Atmospheric Chemistry Dept. (ACD), Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Herrmann
authors.affiliation: Université de Lyon 1, Lyon, F-69626, France; CNRS, UMR5256, IRCELYON, Institut de Recherches sur la Catalyse et l'Environnement de Lyon, Villeurbanne, F-69626, France.
authors.forename: Christian
authors.initials: C
authors.lastname: George
mesh_terms: D005227:Fatty Acids / Q000737:chemistry*; D006812:Humic Substances; D055668:Photochemical Processes; D012623:Seawater / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D005227:Fatty Acids; D006812:Humic Substances