1,860 research outputs found

    Three Years (2008-2010) Measurements of Atmospheric Concentrations of Organochlorine Pesticides (OCPs) at Station Nord, North East Greenland

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    Atmospheric concentrations of organochlorine pesticides (OCPs) have been measured for the first time at Station Nord, North-East Greenland, from 2008 to 2010. The data obtained are reported here. Hexachlorobenzene (HCB), endosulfan I and hexachlorocyclohexanes (HCHs) were the predominant compounds detected in the atmosphere, followed by p,p′-DDE and dieldrin. Chlordane isomers and related compounds (trans- and cis-chlordanes, heptachlor and heptachlor epoxide, trans- and cis-nonachlor) were also detected. Atmospheric concentrations of the investigated compounds were correlated with temperature using the Clausius–Clapeyron equation in order to obtain information about their transport properties. The correlation between atmospheric concentrations and temperature was not significant for endosulfan I, γ-HCH and p,p′-DDT, which indicates that direct transport from direct sources is the dominating transport mechanism for these compounds. A significant correlation with temperature was found for all the other studied pesticides and pesticide degradation products, which indicates that re-emission of these compounds from previously contaminated surfaces is an important factor for the observed variation in concentrations. Pesticide concentrations were also correlated with sea ice cover. Concentrations of the compounds that have not been in use for decades correlated with temperature and ice cover, while concentrations of compounds still in use did not correlate with either of these parameters. These observations indicate that processes such as revolatilization from the open sea surface are important mediating factors in the dynamics of anthropogenic persistent pollutants in the Arctic environment under the expected influence of climate change processes

    Modelling of Mercury in the Arctic with the Danish Eulerian Hemispheric Model

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    International audienceA new 3-D mercury model has been developed within the Danish Arctic Monitoring and Assessment Programme (AMAP). The model is based on the Danish Eulerian Hemispheric Model, which in the original version has been used to study the transport of SO2, SO42- and Pb into the Arctic. It was developed for sulphur in 1990 and in 1999 also lead was included. For the current study a chemical scheme for mercury has been included and the model is now applied to the mercury transport problem. Some experiments with the formulation of the mercury chemistry during the Polar Sunrise are carried out in order to investigate the observed depletion. Some of the main conclusions of the work described in this paper are that atmospheric transport of mercury is a very important pathway into the Arctic and that mercury depletion in the Arctic troposphere during the Polar Sunrise contributes considerably to the deposition of mercury in the Arctic

    Modelling of mercury with the Danish Eulerian Hemispheric Model

    No full text
    International audienceA new 3-D mercury model has been developed within the Danish Arctic Monitoring and Assessment Programme (AMAP). The model is based on the Danish Eulerian Hemispheric Model, which in the original version has been used to study the transport of SO2, SO42? and Pb into the Arctic. It was developed for sulphur in 1990 and in 1999 also lead was included. For the current study a chemical scheme for mercury has been included and the model is now applied to the mercury transport problem. Some experiments with the formulation of the mercury chemistry during the Polar Sunrise are carried out in order to investigate the observed depletion. Some of the main conclusions of the work described in this paper are that atmospheric transport of mercury is a very important pathway into the Arctic and that mercury depletion in the Arctic troposphere during the Polar Sunrise contributes considerably to the deposition of mercury in the Arctic

    Notes on the birds of the tidal lowlands and floodplains of South Sumatra province, Indonesia

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    During an environmental baseline survey of the tidal lowlands and floodplains of South Sumatra Province in 1988-89, a total of 270 bird species was recorded. This paper focuses on wetland species, including those inhabiting swamp forests. No upland forest habitats are found within the region described. The area supports a diverse avifauna, including some globally threatened species that have a core population here, notably Milky Stork Mycteria cinerea, Storm's Stork Ciconia stormi, Lesser Adjutant Leptoptilos javanicus, Black-headed Ibis Threskiomis melanocephatus and Asian Dowitcher Limnodromus semipalmatus. The coast has vital passage and wintering grounds that rank second in importance only to coastal wetlands in Bangladesh for East Palaearctic waders in terms of numbers of birds. Three species were recorded for the first time in Sumatra: Spotted Eagle Aquila clanga, Steppe/Imperial Eagle Aquila nipalensis/heliaca and Spotted Redshank Tringa erythropa, and first Sumatran breeding records were obtained for Javan Pond-heron Ardeola speciosa and White-headed Stilt Himantopus leucocephalus. A few species were observed outside their previously recorded usual habitats. The paper discusses the principal habitats of the area, and the very rapid rate of development that has occurred during the past two decades. Only one wetland area in the province has protection status, Padang-Sugihan. This Wildlife Reserve does not provide habitat for eight out of the eleven globally threatened species recorded in the study area. Consequently the establishment of two additional swamp reserves and bird sanctuary is strongly recommended

    DARA: Assisting Drivers to Reflect on How They Hold the Steering Wheel

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