August 14, 2010 - Smoke and fires across western Canada

Smoke and fires across western Canada

Multiple fires continue to burn throughout British Columbia, Canada, causing smoke to rise in ribbons, streamers and, in some areas, thick plumes. Layers of smoke and haze blanket the land throughout this true-color image, which was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite on August 4, 2010.

The city of Ketchikan, Alaska lies near the center of the far west of the image and the northern-most red hotspots are located in the Yukon Territory. Prince George, the largest city in northern British Columbia, is found to the east of the large cluster of the more southerly hotspots. The fires, which began to burn at the end of July, are located primarily in remote regions with sparse population.

The red areas depict areas of intense heat, which, when coupled with a smoke plume, strongly suggests active fires. Areas of fire containment, where the fire is no longer spreading but is being allowed to burn within a firebreak, cannot be differentiated from uncontrolled fires in this image.

The intensity of a forest fire depends in large part on the species of trees found in the ecosystem as well as the moisture present in both the forest vegetation and the floor debris. The flame of an average fire, burning forest floor, might reach 1 meter (about 3.3 feet) high and can reach or exceed a temperature of 800°C (1472°F). Under the most favorable fire conditions, a blaze can emit 10,000 kilowatts or more per meter of fire front. This would correlate with flame temperatures in excess of 1200°C (over 2000°F) and greater than 50 meters(164 feet) high.

The amount of smoke from a fire also is dependent, in large part, on the type and moisture content of the material burning. Smoke contains liquids, gases and particles of different sizes. The particles can be so small as to easily pass deep into lung tissue. The ozone produced by the reaction of sunlight with gases in the plume can also be harmful to the lungs. On August 4, the day of this image, citizens in selected areas near the fires were evacuated – not only in fear of the flames, but because of the risks posed by smoke-laden air.

Image Facts
Satellite: Aqua
Date Acquired: 8/04/2010
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC