Figure 3.34

Clouds as reflectors. (A) White arrows depict shortwave solar energy interacting with the cloud top. Some shortwave energy is scattered as it passes through the cloud, but most is reflected and scattered back to space. (B) This satellite image shows the albedo of the sky for the month of June 2013. A value of 100 in the color key indicates a reflectivity of 100%. Cloud-free skies, such as those over the Sahara in northern Africa, are dark blue and have low albedo values. Light blue and white areas show cloudy, reflective skies. The tropics and midlatitudes are particularly cloudy and reflective.

(A. David R. Frazier/Science Source)