Graphic by: Yiqi Shao

Rainbows, sunsets and halos; a spectacular display of colors and visuals in the sky called "atmospheric optics". As sunlight (or moonlight) enters the atmosphere, it is either absorbed, reflected, scattered, refracted or diffracted by atmospheric particles or air molecules. These processes, individually or in combination, are responsible for producing most optical effects. This module investigates these particle-light interactions and the assortment of optical effects they produce. The Light and Optics module has been organized into the following sections:

The type of optical effect that results greatly depends upon the type of particles the light encounters and on the wavelength of the light. For this reason, the optical effects discussed in this module have been grouped according to the following classifications of atmospheric particles: air, dust and haze, ice crystals, and water droplets.