Role of Minerogenic Particles in Light Scattering in Lakes and a River in Central New York

Abstract

The role of minerogenic particles in light scattering in several lakes and a river (total often sites) in central New York, which represent a robust range of scattering conditions, was evaluated based on an individual particle analysis technique of scanning electron microscopy interfaced with automated x-ray microanalysis and image analysis (SAX), in situ bulk measurements of particle scattering and backscattering coefficients (b sub p and b sub bp), and laboratory analyses of common indicators of scattering. SAX provided characterizations of the elemental x-ray composition, number concentration, particle size distribution (PSD), shape, and projected area concentration of minerogenic particles (PAV sub m) of sizes >0.4 m. Mie theory was applied to calculate the minerogenic components of b(sub p) (b sub m) and b(sub bp), (b sub b) with SAX data. Differences in PAV(sub m), associated primarily with clay minerals and CaCO3, were responsible for most of the measured differences in both b(sub p), and b(sub bp) across the study sites. Contributions of the specified minerogenic particle classes to b(sub bp) were found to correspond approximately to their contributions to PAV(sub m). The estimates of b(sub m) represented substantial fractions of b(sub m), whereas those of b(sub bm) were the dominant component of b(sub bp). The representativeness of the estimates of b(sub m) and b(sub bm) was supported by their consistency with the bulk measurements. Greater uncertainty prevails for the b(sub bm) estimates than those for b(sub m), associated primarily with reported deviations in particle shapes from sphericity. The PSDs were well represented by the "B" component of the two-component model or a three parameter generalized gamma distribution.

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Document Details

Document Type
Technical Report
Publication Date
Sep 10, 2007
Accession Number
ADA476498

Entities

People

  • Alan Dean Weidemann
  • David O'donnell
  • Feng Peng
  • Mary Gail Perkins
  • Stevel Effler

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Backscattering
  • Chemistry
  • Electron Microscopy
  • Glass Fibers
  • Light Scattering
  • Marine Systems (Military)
  • Measurement
  • Optical Properties
  • Optics
  • Particle Size
  • Particles
  • Refractive Index
  • Scanning Electron Microscopy
  • Scattering
  • Standards
  • World Geodetic System
  • X Rays

Readers

  • Aerosol Science/Aerosol Physics
  • Analytical Mechanics
  • Computational Modeling and Simulation

Technology Areas

  • Microelectronics