On 14 August 2017 three pyroCbs formed in Russia. Himawari-8 detected the smoke plume and pyroCb cloud, as well as the fire hot spots. The first pyroCb cloud (~63.2º N, 117.1ºE) formed around 06:30 UTC . The second pyroCb (~62.8º N, 122.4ºE) formed around 07:00 UTC. The third pyroCb (~61.5º N, 122.1ºE) formed around 8:10 UTC. Starting at 06:00 UTC, the animation below shows Himawari-8 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.
In addition, using Himawari-8 10.4 μm IR channel imagery the cloud-top IR brightness temperatures can be determined. The animation below, starting at0 7:30 UTC on 14 August, shows the brightness temperature for the first pyroCb cloud reaching near -54ºC around 09:00 UTC (orange color enhancement), reaching -52ºC (orange color enhancement) for the second pyroCb, and reaching -50ºC (yellow color enhancement) for the third pyroCb.
A 1-km resolution NOAA-19 AVHRR 10.8 µm Infrared Window image (below; courtesy of René Servranckx) revealed a minimum cloud-top IR brightness temperature of -60.9º C (red color enhancement) for the first pyroCb at 09:39 UTC. Also the second image shows the minimum cloud-top IR brightness temperature of -59.2º C (red color enhancement) at 07:59 UTC for the second pyroCb and -54.5º C (red color enhancement) for the third pyroCb.