PropGen Examples

The script run_propgen_example demonstrates the new system for generating SHDOM optical property files. Scattering tables are made for lognormal size distributions of spherical dust aerosols and gamma distributions of water cloud droplets with make_mie_table, and for gamma distributions of hexagonal plate and rough aggregate ice crystals with make_ice_table. An example particle file (nauru19990707.part) specifies the mass content and effective radius distributions for a horizontally uniform aerosol layer (particle type 1) from the surface to 1.4 km, a broken cumulus water cloud layer (type 2) from 0.59 to 2.03 km, and a cirrus layer made of plates and aggregates (types 3 and 4) from 8.75 to 14.75 km. The two-dimensional (X-Z) cumulus and cirrus cloud distributions are derived from the ARM millimeter-wave cloud radar on Nauru Island. The propgen program reads the particle file and four scattering tables to generate the optical properties file for SHDOM.

The distribution includes an IDL program "" which plots the components of the particle file, the resulting extinction and single scattering fields, and radiance output from SHDOM.

The mass content and effective radius of the four particle types is shown in these figures (click on on figure to enlarge):
Aerosol:     Cloud droplets:
Plate ice crystals:     Aggregate ice crystals:

Example phase functions for the four particle types are shown for 1.64 microns wavelength.

The extinction and single scattering albedo is shown for 0.65 microns and 1.64 microns wavelength.

The optical depth and radiance for three directions is plotted for 0.65 microns and 1.64 microns wavelength.

Last modified: June 19, 2003

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