Atmospheric Optics and Light Scattering


Light interacting with cloud drops and ice crystals in the atmosphere produces atmsopheric optics dsiplayes - rainbows, halos, glories, coronas. Observation of these phenomena give hints about properties of cloud drops, raindrops, and ice crystals - their sizes and orientations.

One of the best atmospheric optics sites is

Simulate atmospheric optics phenomena - HaloSim3 and Iris2 Software

HaloSim runs on PCs with Windows95+. A 24 bit color is desirable. Memory and hard disk requirements are insignificant. The download comes with all data and a set of ready-to-run simulations.

(1) DOWNLOAD "" from (2.38 MB) or /files/
(2) EXTRACT (do not RUN) into a temporary folder.
(3) RUN 'setup.exe'. When prompted chose a folder for the program files or use the suggested default which is usually inside c:\Program Files\….
(4) RUN 'HaloSim361.exe' from the program files folder.

Iris2 software

(1) Download '' here or /files/
(2) EXTRACT into a temporary folder
(3) RUN 'setup.exe'. When prompted chose a folder for the program or use the suggested default.
(4) RUN 'Iris.exe'

Mie scattering

Mie scattering

Discrete Dipole Approximation

DDSCAT code (discrete dipole approximation)

User Guide to the Discrete Dipole Approximation Code DDSCAT.7.0", by B.T. Draine and Piotr J. Flatau. A copy of this document (postscript or pdf) can be obtained from

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License