Optical Cross-Sections of Marine Particles.
Abstract
Our objective is to conduct a comprehensive study of the optical properties of marine microorganisms and other biogenic particles in order to determine their optical cross-sections and contribution to absorption and scattering by sea water. Our major effort during the last year was aimed at quantifying diel changes in scattering and absorption cross-sections of phytoplankton cells. This study is related to our hypothesis that the relatively large diel cycle in the beam attenuation coefficient that has been observed in the ocean is in part caused by diel change in the size and refractive index of cells comprising the phytoplankton community. Another effort was focused on testing the applicability of the dynamic light scattering (DLS) technique for characterizing the size distribution of small marine particles (< 5 microns) including the submicron range. While we previously used this technique for studying the cultures of heterotrophic marine bacteria, this time we focus our attention on natural assemblages of marine particles. This effort is related to the hypothesis that submicron particles make major contribution to particulate backscattering in the ocean. Another major effort was aimed at examining marine cyanobacteria which represent small autotrophic organisms from the picoplankton size range. We also assessed the effect of gas microbubbles on light scattering in the upper ocean. (AN)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1993
- Accession Number
- ADA291386
Entities
People
- Dale A. Kiefer
- Dariusz Stramski
Organizations
- University of Southern California