Typhoon Ioke in the Western Pacific

This infrared image shows Typhoon Ioke in the Western Pacific, from the Atmospheric Infrared Sounder AIRS on NASA Aqua satellite in August, 2006.

Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

http://photojournal.jpl.nasa.gov/catalog/PIA00511