Thick blue-gray smoke and haze rise from multiple fires burning the Southern Interior Forest Region of British Columbia, Canada. This true-color image was captured by the Moderate Imaging Spectroradiometer (MODIS) aboard the Aqua satellite as it passed over the region on August 4, 2010, as nearly 400 individual fires were reported on the ground. Smoke from these fires has been blamed for poor air quality in Vancouver, Canada, and in Washington state and Montana, USA.
The town of Kamloops lies in the lower right corner of the image, the town of Cariboo to its north, and Bonaparte Lake lies on the far right edge of the image and northeast of the two towns. On the same day this image was taken, but after the satellite overpass, over 60 properties in the Bonaparte Lake area came under emergency evacuation due to new, rapidly spreading fires.
The red hotspots and heavy smoke clustered near the center of the image indicates large fires burning in remote, forested areas. According to British Columbia Ministry of Forests and Range maps, these forests are moderately to severely damaged by the mountain pine beetle, Dendroctonus ponderosae. Although haze and smoke nearly obscures land, close examination under high resolution reveals patterns of green interspersed by areas of dull red and light grey coloration. In pine forests, green indicates healthy trees, red indicates pines whose needles are turning red as they die, and grey indicates dead trees which have lost needles. In British Columbia, it is estimated that, as of 2009, the areas under red-attack and grey-attack measured about 16.3 million hectares – or nearly 17% of the land area of the entire province.
The presence of pine beetle damage creates a significant risk of fire ignition, and experts state that, depending on the stage of attack, infested forests may burn faster and hotter. In addition, the summer of 2010 has been both extremely hot and dry. Under such conditions, afternoon summer storms, which typically bring lightning strikes but little rain, can ignite fires immediately or cause smoldering in the thick duff layer on forest floors, igniting fires weeks later. Summer recreational use of wilderness also increases risk. All these factors have been thought to play a role in the fires seen here.