Dry Times in North America

(press release). This article from 2000 describes how scientists use data from satellites and rain gauges along with tree-rings and lakebed sediments to understand and predict drought in North America.">

This page contains archived content and is no longer being updated. At the time of publication, it represented the best available science.

Physical Processes that Cause Drought

Dry soil has the opposite effect on rainfall. As the temperature rises during the day, the air near the Earth's surface heats up and rises, but does not contain enough moisture to form rainclouds. As each day passes more moisture is removed from the ground, enhancing the effect. (Animation courtesy Susan Byrne, NASA GSFC)

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