On 12 September 2017 a pyroCb formed in British Columbia. GOES-15 detected the smoke plumes and pyroCb cloud, as well as the fires hot spot. The pyroCb cloud (~50.4º N, 110.3ºW) formed around 0:00 UTC . Starting at 22:00 UTC on 11 September, the animation below shows GOES-15 0.63 µm visible (left) and 3.9 µm shortwave IR (right) . In the shortwave IR images, the red pixels indicate very hot IR brightness temperatures exhibited by the fire source regions.
GOES-15 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)
Usually GOES-15 10.7 μm IR channel is used to find the cloud-top IR brightness temperature. However, the resolution of this satellite did not provide a brightness temperature lower than -40ºC.
A 1-km resolution NOAA-19 AVHRR 10.8 µm Infrared Window image (below;courtesy ofRené Servranckx) revealed a minimum cloud-top IR brightness temperature of -47.8º C (green color enhancement) for the pyroCb at 0:40 UTC on 12 September.
NOAA-19 AVHRR 0.64 µm visible (top left), 3.7 µm shortwave IR (top right), 10.8 µm IR window (bottom left) and false-color RGB composite image (bottom right)