Photography : Land & Sky: Inversion of Light
Different layers of air create an almost sedimentary-looking pattern of light and dark mountains. Cerro Tololo in Chile is an excellent place for observing an interesting atmospheric phenomenon called the inversion layer. This is a layer of warmer air that sits on top some cooler air closer to the surface. It prevents convection, acting like a cap and trapping the air beneath it. This means any smoke, dust, or other air-born particles are also trapped in the bottom layer. The excess smoke and dust scatter sunlight, making the cooler air beneath look "thicker" than the air above it.
The index of refraction (how much the air bends light) increases with lower temperatures, so this layer of cooler air beneath the inversion layer is like a thick lense and bends light to produce weird effects like the green flash, distorted Sun and Moon, and mirages.