The
Amsterdam
Hester Volten*, Olga
Muñoz#, Joop Hovenier*, Rens Waters*
*Astronomical Institute “Anton Pannekoek”,
University of Amsterdam, Netherlands
#Instituto de Astrofísica de Andalucía, CSIC, Granada,
Last update: March 2008
Table of content
Amsterdam Light Scattering Database
Tables
Articles and background information
Aerosol particles
In recent years a considerable
amount of experimental single scattering matrices as functions of the
scattering angle have been obtained with the light scattering facility in
Amsterdam, for samples of randomly oriented small mineral particles in air
(aerosol particles) with broad ranges of sizes and shapes. From these data, it
has become clear that particle shape is highly important in determining the
overall light scattering behavior of these samples.
To
provide an incentive for the use of our data in further research and
applications, we have decided to make our experimental data more easily
available by storing our data in digital form in this database. All data have
been previously published in scientific journals. The database contains the
following data for several samples of mineral aerosol particles in random
orientation:
1. Tables of scattering matrix elements as functions of the
scattering angle from at most 3 to 174 degrees at two wavelengths, 441.6 nm and
632.8 nm.
2. Tables of size distributions
as measured with a laser diffraction method.
3. Scanning Electron Microscope
(SEM) images of the particles that are indicative of their shape
characteristics.
4. Information about the
origin, color, composition and/or the complex refractive index of the samples,
when available.
Information
on the accuracy of the data is provided, whenever possible.
We intend to update this
database regularly with new measured scattering matrix results.
Hydrosol particles
Scattering
data for hydrosol particles are also available in the database: 15 types of
phytoplankton and two types of mineral particles. The information for these particles
is more limited than for the aerosol particles. The database contains the following data
for several samples of hydrosol particles in random orientation:
1.
Tables of the scattering function and the degree of linear polarization for
incident unpolarized light, as functions of the
scattering angle from 20 to 160 degrees at a wavelength of 632.8 nm.
2. Information or estimates
pertaining to the name, classification, size, shape, and complex refractive
index of the samples, when available.
Organization of the database
In the tables below you find the light scattering database. In the left column the various samples are listed. They are linked to a "Fact and Figures" page, where you can find information about the samples, e.g., about their composition, refractive index, etc. In addition, figures of scattering matrix elements and size distributions can be found there. The scattering matrix element data are given in a tabular form, through links in adjacent columns for measurements using red light (632.8 nm), and, whenever available, for measurements using blue light (441.6 nm). Also links to Scanning Electron Microscope (SEM) images or Transmission Electron Microscope (TEM) images and tables of the size distributions are provided, when available. We note that the laser diffraction size distributions were obtained without assumptions about the refractive indices of the materials of the particles.
Click
here for:
general
information about the composition and
refractive index,
general
information about the aerosol SEM images,
the
definition of the scattering matrix,
an
explanation of the normalization of the
scattering matrix,
an
extensive explanation of the size distributions.
In
addition to data for individual samples, we also provide average scattering
matrices composed of combined data, and synthetic matrices that cover a
complete scattering angle range from 0 to 180 degrees.
Lastly,
we would like to remark the following:
1. When we refer to log r, r
refers to radii of projected-surface equivalent spheres and is always expressed
in micrometers.
2. For refractive indices, we
use m=n-ik, with n,k larger or equal to 0 (Van de Hulst, 1957,"Light scattering by small
particles", Wiley, NewYork).
3. Different conventions are
used for Stokes parameters and, consequently, for (the sign of) F34/F11 .
We always use the convention following Van de Hulst,
1957 (see Hovenier and Van der
Mee, Astronomy and Astrophysics, 128, 1-16, 1983, and
the book Transfer of Polarized Light in Planetary Atmospheres, Basic Concepts
and Practical Methods, by J.W. Hovenier, C. van de Mee, and H. Domke, Kluwer Academic Publishers, Dordrecht,
2004).
4. The values of all aerosol
scattering functions F11 have been normalized to 1 at a
scattering angle of 30 degrees. The values of all hydrosol scattering functions
F11 have been normalized to 0.00841 (
Amsterdam
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AEROSOL PARTICLES |
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SIZE DISTRIBUTION |
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Average Matrices and Synthetic matrices |
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Test particles |
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COSMIC DUST ANALOGS – FLUFFY AGGREGATES |
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HYDROSOL PARTICLES |
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Articles and background information
The
articles below are posted with permission from their publishers. Single copies
of an article can be downloaded and printed only for the reader's personal
research and study.
§
The
aerosol data in this database have been published in these
articles.
§
The
hydrosol data in this database have been published in this article.
§
More
information about the database can be found in these
articles.
§
More
information about the experimental setup can be found here.
§
Pictures of the experimental setup, and more.
§
Links to other interesting light scattering websites and databases.
Questions or comments?
We welcome all
feedback!
Please e-mail Hester
and Olga.