The 2015 Wildfire Season is off to a quick start in Alaska (continuing an observed trend). This map (from this url) shows more than 300 active fires over Alaska at 2000 UTC on 29 June 2015. This graph (from the Alaska Climate Info facebook page) compares early burn acreage in 2015 to that in 2004 (the year with the most acreage burned — see this graph, courtesy of Uma Bhatt, University of Alaska-Fairbanks).
The 3.74 µm infrared imagery from early morning on 29 June 2015 (top) shows numerous hot spots in the region surrounding the Yukon River (visible in the imagery south of the Kotzebue Sound). Visible Imagery from the same time, above, shows an extensive pall of smoke over central Alaska.
Smoke from fires over Alaska and over northern Canada (image from 28 June 2015) have led to considerable smoke over the northern Plains of the Continental United States. The plume on Sunday 28 June (above) was fairly narrow; however, a larger plume is now moving south (GOES Imagery below, then MODIS True-Color displayed in SSEC‘s RealEarth). (MODIS Today imagery of this event is also available here.)
Day-time detection of smoke plumes is not difficult with visible imagery. At night, however, smoke detection is a challenge. The Day Night Visible Band on Suomi NPP can detect smoke when Lunar Illumination is high (although detection is limited to one pass per night). Smoke is otherwise mostly transparent to infrared channels on the GOES Imager, however. Websites such as NOAA/NESDIS’s IDEA and the GASP site are helpful. The GASP data uses single-channel detection only — visible data.
Visible Imagery from GOES-15, below, underlines the extensive region covered by smoke over northern Canada. Note that the smoke becomes less distinct with time as the sun rises higher in the sky because forward scattering by smoke particles of visible light is more effective than backward scattering.