title: Vertical variability of seawater DMS in the South Pacific Ocean and its implication for atmospheric and surface seawater DMS.
abstract: Shipboard measurements of atmospheric dimethylsulfide (DMS) and sea surface water DMS were performed aboard the R/V Onnuri across the South Pacific from Santiago, Chile to Fiji in February 2000. Hydrographic profiles of DMS, dissolved dimethylsulfoniopropionate (DMSP(d)), and particulate DMSP(p) in the upper 200m were obtained at 16 stations along the track. Atmospheric and sea surface water DMS concentrations ranged from 3 to 442pptv and from 0.1 to 19.9nM, respectively; the mean values of 61pptv and 2.1nM, respectively, were comparable to those from previous studies in the South Pacific. The South Pacific Gyre was distinguished by longitudinal-vertical distributions of DMS, DMSP(d), and DMSP(p), which was thought to be associated with the characteristic modification of biological activities that occurs mainly due to significant change in water temperature. The averaged DMS maximum appeared at 40m depth, whereas DMSP(p) and DMSP(d) maxima coincided with that of dissolved oxygen content at 60-80m. The sea-to-air fluxes of DMS were estimated to be 0.4-11.3micromold(-1)m(-2) (mean=2.8micromold(-1)m(-2)). A fairly good correlation between atmospheric DMS and sea-to-air DMS flux indicated that atmospheric DMS concentration was more sensitive to change in physical parameters than its photochemical removal process or surface seawater DMS concentrations.
authors.affiliation: Department of Environmental Science, Hankuk University of Foreign Studies, Yongin, South Korea.
authors.forename: Gangwoong
authors.initials: G
authors.lastname: Lee
authors.forename: Jooyoung
authors.initials: J
authors.lastname: Park
authors.forename: Yuwoon
authors.initials: Y
authors.lastname: Jang
authors.forename: Meehye
authors.initials: M
authors.lastname: Lee
authors.forename: Kyung-Ryul
authors.initials: KR
authors.lastname: Kim
authors.forename: Jae-Ryoung
authors.initials: JR
authors.lastname: Oh
authors.forename: Dongseon
authors.initials: D
authors.lastname: Kim
authors.forename: Hi-Il
authors.initials: HI
authors.lastname: Yi
authors.forename: Tong-Yup
authors.initials: TY
authors.lastname: Kim
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D010140:Pacific Ocean; D012623:Seawater / Q000737:chemistry*; D013440:Sulfides / Q000032:analysis*; D013452:Sulfonium Compounds; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D013440:Sulfides; D013452:Sulfonium Compounds; D014874:Water Pollutants, Chemical; C068078:dimethylpropiothetin; C004784:dimethyl sulfide