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Gioia, Rosalinda; Macleod, Matthew; Castro-jimenez, Javier; Nizzetto, Luca; Dachs, Jordi; Lohmann, Rainer; Jones, Kevin C.. |
A diel (24-h) cycle with daytime atmospheric concentrations higher than nighttime concentrations by a factor of 1.5-3 was observed for several low molecular weight polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in remote areas of the tropical South Atlantic during a cruise in October-November 2005. In contrast, high molecular weight PCBs and PAHs did not display diurnal variability. A model which has successfully explained diel variability of persistent organic pollutants (POPs) over land could not reproduce the observed diel cycle by considering variability in temperature, atmospheric OH radical concentrations, atmospheric boundary layer height and wind speed as causal factors. We used the model to conduct two bounding... |
Tipo: Text |
Palavras-chave: Persistent organic pollutants (POPs); Diurnal cycle; Polychlorinated biphenyls (PCBs); Polycyclic aromatic hydrocarbons (PAHs); South Atlantic. |
Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00645/75721/76676.pdf |
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Mejanelle, Laurence; Riviere, Beatrice; Pinturier, Laurence; Khripounoff, Alexis; Baudin, Francois; Dachs, Jordi. |
Hydrocarbons were analyzed in sediments from the Congo River deep-sea fan, from the Congo River, and in sinking particles collected by sediment traps 40 m above the sediment. Studied sites encompassed three lobes of decreasing age of formation along the canyon: sites A, F and C and a another lobe system, disconnected from the active channel since 4 ka, Site E. Terrestrial long-chain odd n-alkanes were dominant in all sediments of the lobe system. Unsaturated terpenoids sourced by higher plants, such as gammacerene, lupene, ursene and oleanene, were also detected. At site C, characterized by high accumulation rates (10–20 cm yr−1), the organic matter spends less time in the oxic layer than at other sites and high phytadiene concentrations (10 to 17 μg... |
Tipo: Text |
Palavras-chave: Congo fan; Hydrocarbons; NAH; Hopanes; Hopenes; Sediments; Turbidite system. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00388/49902/50472.pdf |
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