Union, Illinois Lightning Strike
November 22, 2008
Photographer: Donald Cox
Summary Author: Donald Cox
The photo above shows a lightning strike (triple strike) during a thunderstorm in Union, Illinois on July 18, 2007. When the lower portion of a negatively charged cumulonimbus cloud reacts to the generally positively charged Earth’s surface, discharges such as this occur. The amount of the humidity in the air and the strength of the electrical field each play a role in determining the color spectrum of lightning.