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Detailed Reference Information |
Reid, E.A., Reid, J.S., Meier, M.M., Dunlap, M.R., Cliff, S.S., Broumas, A., Perry, K. and Maring, H. (2003). Characterization of African dust transported to Puerto Rico by individual particle and size segregated bulk analysis. Journal of Geophysical Research 108: doi: 10.1029/2002JD002935. issn: 0148-0227. |
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As part of the Puerto Rico Dust Experiment (PRIDE), airborne and surface dust particle samples from Africa were collected and subjected to bulk elemental and single-particle analysis. Airborne samples were collected on polycarbonate filters at various altitudes and underwent single-particle scanning electron microscopy with energy dispersive analysis with X-rays (EDAX) to derive elemental ratios of key soil elements. Particle chemistry was related to size and morphological characteristics. At the principle surface site, particles were collected on a Davis Rotating Drum (DRUM) cascade impactor strips in eight stages from 0.1 to 12 ¿m at 4 hour time resolution. These samples were subjected to X-ray florescence (XRF) to determine bulk elemental composition from Al through Zn. The elemental data showed good correlation between the DRUM and the aircraft samples. Cluster analysis of single-particle data resulted in 63 statistically significant clusters. Several clusters can be easily related to their parent mineralogical species. However, as dust particles are to a large extent aggregates, most clusters are based on a continuum of varied mineralogical species and cannot be easily categorized. With 60,500 total particles counted from the airborne filters, a statistically significant number of large particles could be analyzed. Estimated mean surface area modal diameter is ~5 ¿m, with an average aspect ratio of 1.9. An apparent change in source region is seen in the morphological data and non alumino-silicate minerals but is not seen in the aluminum to silicon ratio. We suspect homogenization during long-range transport. |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Atmospheric Composition and Structure, Aerosols and particles (0345, 4801), Atmospheric Composition and Structure, Geochemical cycles, Atmospheric Composition and Structure, Transmission and scattering of radiation, Atmospheric Composition and Structure, Troposphere--constituent transport and chemistry |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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