Fires in southern Idaho

GOES-15 (left) and GOES-13 (right) 0.63 µm visible channel and 3.9 µm shortwave IR channel images (click image to play animation)

GOES-15 (left) and GOES-13 (right) 0.63 µm visible channel and 3.9 µm shortwave IR channel images (click image to play animation)

A cluster of 4 major fire complexes (Pony, Elk, McCan, and Beaver Creek) east of Boise in southern Idaho began to exhibit extreme fire behavior on during the afternoon and evening hours on 10 August 2013. A comparison of GOES-15 (GOES-West) and GOES-13 (GOES-East) 1-km resolution 0.63 µm visible channel and 4-km resolution 3.9 µm shortwave IR images (above; click image to play animation) showed 2 different perspectives of the many dense smoke plumes and the eventual development of a well-defined pyrocumulonimbus (pyroCb) cloud whose source appeared to be the Elk Complex. On the shortwave IR images, the hottest fire pixels are enhanced red. These fires were belived to have been caused by lightning on 08 and 09 August.

The corresponding 4-km resolution GOES-15 and GOES-13 10.7 µm IR channel images (below; click image to play animation) revealed that the pyroCb cloud first began to exhibit IR brightness temperatures colder than -20º C  (cyan color enhancement) after 20:00 UTC or 1:00 PM local time, -40º C (green color enhancement) after 20:20 UTC or 1:30 PM local time, and -60º C (darker red color enhancement) after 00:30 UTC or 6:30 PM local time.

GOES-15 (left) and GOES-13 (right) 10.7 µm IR channel images (click image to play animation)

GOES-15 (left) and GOES-13 (right) 10.7 µm IR channel images (click image to play animation)

250-meter resolution MODIS true-color and false-color Red/Green/Blue (RGB) images from the SSEC MODIS Today site (below) offered a very detailed view of the gray-colored smoke plumes streaming northward from the various fire complexes, as well as the brighter white pyrocumulonimbus cloud which was being produced by the Elk Complex.On the MODIS false-color image, the large fire burn scars showed up as darker shades of red, while the actively-burning fires appeared lighter red to white.

MODIS true-color and false-color RGB images

MODIS true-color and false-color RGB images

Several hours later, a comparison of 1-km resolution Suomi NPP VIIRS 3.74 µm and 4-km resolution GOES-13 3.9 µm shortwave IR images just after 4 AM local time (below) demonstrated the advantage of higher spatial resolution for detecting the true location of fire “hot spots” (black to yellow to red color enhancement). Note that there is also a significant westward displacement of the largest hot spot cluster on the GOES-13 image — there is a known co-registration error with the GOES 3.9 µm channel imagery (see this CIMSS Satellite Blog post), which is in the process of being investigated and corrected.

Suomi NPP VIIRS 3.74 µm and GOES-13 3.9 µm shortwave IR images

Suomi NPP VIIRS 3.74 µm and GOES-13 3.9 µm shortwave IR images

 

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