Showing papers by "Leonard A. Barrie published in 1991"
TL;DR: In this paper, a series of daily atmospheric aerosol samples collected in southern Sweden between 9 February and 30 May 1988 were used to classify the samples according to source region: Northwest, Western Europe, East, Eastern Europe, or a combination of two regions.
Abstract: Pb 206 /Pb 207 and Pb 208 /Pb 207 isotope ratios were measured in a series of daily atmospheric aerosol samples collected in southern Sweden between 9 February and 30 May 1988. The ratios were observed to vary considerably, depending on the origin of air. 5-day back-trajectories were used to classify the samples according to source region: Northwest, Western Europe, East, Eastern Europe, or a combination of two regions. Significant differences in the isotope ratios were found. Unique signatures based on the Pb 206 /Pb 207 and Pb 208 /Pb 207 ratios could be assigned for each region. The signatures were generally consistent with isotope ratios of Swedish and other European gasolines, and with literature values of the isotope ratios of economically significant lead ores used in Europe. A comparison was made between the regional signatures and the Pb 206 /Pb 207 ratios observed in Arctic aerosol samples. Excellent agreement was observed between the Arctic Pb 206 /Pb 207 ratios (1.160) and an average source signature (1.156) calculated from observations in this study using equal contributions from Western Europe, Eastern Europe, and the East as predicted by a chemical transport model. DOI: 10.1034/j.1600-0889.1991.00004.x
175 citations
TL;DR: In this paper, the types, concentrations, and vapor-particle relationships for polycyclic aromatic hydrocarbons (PAH) and oxygenated compounds, Organochlorine (OC) pesticides, and polychlorinated biphenyls (PCB) were determined.
Abstract: In February–April 1988 we collected air samples at Alert in the Canadian Arctic (82.5°N, 62.3°W) to determine the types, concentrations, and vapor-particle relationships for polycyclic aromatic hydrocarbons (PAH) and oxygenated compounds, Organochlorine (OC) pesticides, and polychlorinated biphenyls (PCB). Samples were taken using a glass fiber filter-polyurethane foam train and were analyzed by capillary gas chromatography using mass selective and electron capture detection. PAH and oxygenated compounds included dibenzofuran, biphenyl, fluorene, phenanthrene, 9-fluorenone, fluoranthene, benzofluoranthenes, pyrene, chrysene, benzopyrenes, indeno[cd]pyrene, benzo[ghi]perylene, 2-methyl phenanthrene, benz[a]anthracene, and anthracene (given in order of relative abundance, highest to lowest). OC compounds included hexachlorocyclohexanes (HCH), hexachlorobenzene, pentachlorobenzene, PCB, polychlorocamphenes, chlordanes, and the dichlorodiphenyl-trichloroethane (DDT) group (given as above). The concentration ratios of α-HCH/γ-HCH (5.2–9.8) and trans- to cis-chlordane (0.78–1.29) are reported. Compounds having estimated liquid-phase saturation vapor pressure (pL0) ≥ 10-3 Pa at the average sampling temperature (245 K) were almost entirely gaseous. Those from 10-6 ≤ pL0 ≤ 10-3 Pa were distributed between the particle and gas phases, whereas little or no gaseous component was evident for compounds having pL0 ≤ 10-6 Pa. The particle-vapor distribution of PAH and OC compared favorably to the Junge-Pankow model.
114 citations
01 Jan 1991
TL;DR: The chemical composition and physical form of snowfall is controlled by a range of complex physical and chemical processes occurring on spatial scales ranging from the atomic dimensions of a water molecule (10−10 m) to the size of precipitating cloud system (105 to 106 m) and on temporal scales from the time to grow ice particles by diffusion (1 to 102 s), to the lifetime of a precipitating Cloud system (104 to 105s) as discussed by the authors.
Abstract: The chemical composition and physical form of snowfall is controlled by a range of complex physical and chemical processes occurring on spatial scales ranging from the atomic dimensions of a water molecule (10−10 m) to the size of precipitating cloud system (105 to 106 m) and on temporal scales ranging from the time to grow ice particles by diffusion (1 to 102 s) to the lifetime of a precipitating cloud system (104 to 105s). The processes occur in a turbulent atmosphere and involve three phases of water. In the last thirty years, the cloud physics research community has made major advances in our understanding of snow formation. In particular, the role of the ice phase has received considerable attention since in extra-tropical regions, it plays a key role. There are several comprehensive texts in this field (Mason, 1971; Hobbs, 1974; Pruppacher and Klett, 1980) as well as symposia proceedings(e.g. Cloud Physics, 1990) which the reader is encouraged to consult as background to this review.
26 citations
TL;DR: In this article, distribution analyses of measured chemical composition variables, including several trace elements and ionic species, were conducted for filter samples of airborne particles at three Arctic sites, Alert, Mould Bay and Igloolik in the Northwest Territories of Canada.
14 citations