Accession Number:

ADA504041

Title:

Characterizations of Minerogenic Particles in Support of Modeling Light Scattering in Lake Superior Through a Two-Component Approach

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV

Report Date:

2009-01-01

Pagination or Media Count:

16.0

Abstract:

The role of suspended minerogenic particles in light scattering in eastern Lake Superior and Keweenaw Bay II sites during July of 2006 was evaluated with an individual particle analysis technique scanning electron microscopy interfaced with automated image and X-ray analyses, SAX, along with bulk paniculate scattering and backscattering coefficients bp and bbp and chlorophyll a concentration ChI. SAX measurements provide light-scattering attributes of minerogenic particles, including chemical composition and particle size distribution PSD. The data were use calculations for estimations of minerogenic scattering and backscattering coefficients bm and bb,m. The bay had higher concentrations of minerogenic particles and higher values of bm, bb,m. bbp, and the backscattering ratio bbp bp than the pelagic sites. Minerogenic scattering was primarily attributable particles in the size range of I -10 mm. The PSDs deviated from the Junge pattern of monotonic increase of particle numbers with decreasing estimates of bm and bb,m combined with those of organic particulate components, as represented by empirical Case 1 bio-optical models, showed closure with bp and bbp, supporting the credibility of the SAX -Mie approach. Variations in the bbp bp ratio are strongly related to spatial different contributions of phytoplankton vs. minerogenic particles to scattering, with higher values observed where the minerogenic component is more important. SAX can advance the understanding of optical variability by establishing the contributions of well-defined minerogenic constituents that strongly influence optical properties.

Subject Categories:

  • Hydrology, Limnology and Potamology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE