title: Surface waters as a sink and source of atmospheric gas phase ethanol.
abstract: This study reports the first ethanol concentrations in fresh and estuarine waters and greatly expands the current data set for coastal ocean waters. Concentrations for 153 individual measurements of 11 freshwater sites ranged from 5 to 598 nM. Concentrations obtained for one estuarine transect ranged from 56 to 77 nM and levels in five coastal ocean depth profiles ranged from 81 to 334 nM. Variability in ethanol concentrations was high and appears to be driven primarily by photochemical and biological processes. 47 gas phase concentrations of ethanol were also obtained during this study to determine the surface water degree of saturation with respect to the atmosphere. Generally fresh and estuarine waters were undersaturated indicating they are not a source and may be a net sink for atmospheric ethanol in this region. Aqueous phase ethanol is likely converted rapidly to acetaldehyde in these aquatic ecosystems creating the undersaturated conditions resulting in this previously unrecognized sink for atmospheric ethanol. Coastal ocean waters may act as either a sink or source of atmospheric ethanol depending on the partial pressure of ethanol in the overlying air mass. Results from this study are significant because they suggest that surface waters may act as an important vector for the uptake of ethanol emitted into the atmosphere including ethanol from biofuel production and usage.
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA. Electronic address: averyg@uncw.edu.
authors.forename: G Brooks
authors.initials: GB
authors.lastname: Avery
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Foley
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Carroll
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Jesse Alan
authors.initials: JA
authors.lastname: Roebuck
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Guy
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Ralph N
authors.initials: RN
authors.lastname: Mead
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kieber
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Joan D
authors.initials: JD
authors.lastname: Willey
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Skrabal
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: J David
authors.initials: JD
authors.lastname: Felix
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Mullaugh
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina, Wilmington, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Helms
mesh_terms: D063366:Estuaries; D000431:Ethanol / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis; D005740:Gases; D012623:Seawater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005740:Gases; D014874:Water Pollutants, Chemical; D000431:Ethanol
keywords: Atmosphere; Ethanol; Surface waters