Wildfire

From ArticleWorld

The word wildfire refers to an uncontrolled fire, commonly occurring in wild land areas, but often threatens homes as well. The word wildfire originated as a synonym for the Greek ‘’fire’’. This was a napalm-like substance used in medieval warfare.

Causes

Lightening strikes, human carelessness, and arson are the leading causes of wildfires. Draught conditions are also a contributor. Absolute fire suppressions policies, in the United States, resulted in fuel buildup, which in turn resulted in high intensity fires. Controlled burns are now implemented to get rid of excess fuel, as well as to stimulate the growth of trees that require fire as part it their life cycle. In the 19th century, the practice of leaving ‘’slash’’, or misshapen wood that is undesirable to loggers, provided the fuel for several devastating fires.

Wildfire behaviors

Wildfires can travel by one of three means. A crawling fire spreads along the ground, using grass and bushes for fuel. A crown fire travels very quickly through the tops of the trees. These can be especially dangers to living things below, as most of the available oxygen is suck upward to feed the fire. A jumping, or spotting, fire travels by branches and leaves being carried on the wind. This can enable a fire to jump roads, rivers, and even firebreaks intended to stop the fire’s progress. Some places, like southern California have naturally occurring weather patterns that contribute to the spreading of wildfires. The Santa Ana winds can propel wildfires at very high speeds, and can consume land at 1000 acres per hour.

Atmospheric effects

The smoke plumes created by wildfires contribute to pollution and increase the absorption of the sun’s radiation. It was previously thought that most of the pollution in the stratosphere came from volcanoes and commercial aircraft. In 2003, air samples were taken and shown to contain levels of carbon monoxide at levels thirty times higher than can be accounted for by those two sources. Additional studies showed that the plumes of smoke from wildfires do indeed reach the stratosphere. As a result, the particles get stuck above the weather that might have returned them to earth.