Figure 2.28

Diffuse light. The pink and orange glow we see before the Sun rises or sets is a result of light scattering in the atmosphere. When the solar altitude is low (see Section 2.1), sunlight interacts with more molecules and aerosols because it is passing through more atmosphere (see Figure 2.5). These materials scatter long wavelengths of pink and orange, allowing us to perceive them. In mountainous regions, diffuse light is called alpenglow. This photo, taken before sunrise, shows Mont Blanc Massive and Lac Blanc in France.