The sky can be clear and blue or hazy and white.
Red sunsets are a beautiful manifestation of the scattering and attenuation of sunlight.
Clouds can appear white, grey, or dark depending on conditions. The rainbow and ice-particle displays like sundogs and light pillars are less frequent. Light scattering and attenuation can be used to investigate the atmosphere using a remote-sensing instrument called a lidar. Profiles of these atmospheric components as a function of altitude or location are necessary for weather forecasting, climate modeling, and environmental monitoring. A lidar transmits short pulses of laser light into the atmosphere.