NASA
Nasa Earth Observatory: Clouds in a Clear Sky
This article introduces the different layers of the atmosphere and the clouds that are formed there. Scientists use instruments such as the SAGE 11 that help to measure amounts of sunlight, water vapor, and other conditions that affect...
Other
Northern Michigan University: Cirrus Clouds
This concise site draws a connection between cirrus clouds and upcoming weather. It also touches on cloud composition and why cirrus clouds are the fastest moving clouds.