This satellite image shows both dust and clouds in the atmosphere above Japan on April 18, 2006. The dust traveled to Japan from the Gobi Desert.
Click on image for full size
Image Courtesy of NASA's Earth Observatory

Aerosols and Cloud Formation

In order for clouds to form, water droplets in the atmosphere need a surface to condense upon. There are millions of tiny particles floating in the air that can provide this surface, and these particles are called aerosols. They are 100 times thinner than a human hair! Aerosols come from soil, dust, sea salt, or air pollution from cars, power plants, and factories.

The number of particles that are in the atmosphere affect the number of cloud particles that can form. If there is a high number of aerosols in the atmosphere, then a high number of cloud droplets can form. These cloud droplets will also be smaller because the water is divided between more cloud droplets. When this happens, the clouds usually do not produce precipitation.

Different types of clouds and the amount of clouds in the atmosphere may have different impacts on climate. Scientists are still exploring these topics.

Last modified October 17, 2008 by Randy Russell.

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