Arturo Quirantes,
Stewart Bernard:
Light scattering models for modelling algal particles as
a collection of coated and/or nonspherical scatterers
Journal
of
Quantitative Spectroscopy and Radiative Transfer 100, 315-324 (2006) [doi:10.1016/j.jqsrt.2005.11.048]
ABSTRACT:
Ocean
reflectance or ocean colour measurements are an important tool for
oceanographic studies of phytoplankton dynamics. Theoretical models
based on homogeneous, spherical particles underestimate algal
backscattering and thus reflectance values. It is our understanding
that more advanced light scattering methods must be employed, both
for refractive index retrieval (Mie, Aden-Kerker) with inverse
models, and for backscattering calculations (EBCM). The measured
optical properties of a monospecific bloom of the marine brown tide
pelagophyte Aureococcus
anophagefferens are used to
compare
the effects of assuming various simulated particle geometries.
Computational results from polydisperse, coated spherical particles
show results that compare better to experimental reflectance values
than calculations based on homogeneous spheres. No noticeable change
in simulated reflectance values is observed when a randomly oriented
coated spheroidal (rather than spherical) geometry is assumed for the
particle population. Our results suggest that a layered spherical
geometry, based on Aden-Kerker theory, can adequately reproduce
experimentally determined light scattering properties even supposedly
shape-sensitive properties such as the backscattering coefficient.
Keywords: Light
scattering; EBCM; nonspherical particles; algae