PyroCb in Saskatchewan and Alberta

There were two notable pyrocumulus clouds that developed on 22 May 2015 in western Canada: the first in Saskatchewan near the eastern border (56.23º N, 109.82º W), and the second in western Alberta (54.85º N, 110.38º W). The fire in Alberta produced a pyroCb, and covered an area of roughly 200 square kilometers with flames only 40 km from the nearest community, Cold Lake. Another early-season fire produced a pyrocumulus cloud over Saskatchewan, Canada. The fire depicted above was in the northern provincial forest and covered about 225 hectares of land. As of 22 May, there were 21 active wildfires burning across Saskatchewan.

The fire signature was detected by GOES-15 0.63 µm visible channel and 3.9 μm shortwave IR channel imagery (below; click to play animation) which showed the growth of the smoke starting at 23:00 UTC, as the fire began to exhibit hot shortwave IR brightness temperatures shown as red pixels.

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

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

GOES-15 10.7 μm IR channel images (below; click to play animation) showed the pyroCb cloud-top IR brightness temperatures. The pyroCb in Saskatchewan exhibited a minimum  IR brightness temperature of -500 C (yellow color enhancement) . On the other hand, the pyroCb in Alberta only exhibited a minimum IR brightness temperature of -300 C (darker blue color enhancement).

GOES-15 10.7 μm IR images (click to play animation)

GOES-15 10.7 μm IR images (click to play animation)

The first image below was published by the Canadian Natural Resources division on May 22, the day of this pyroCb event. It clearly indicates the high Fire Weather Index (red) for much of the prairie provinces of Canada. The second image below shows the locations of  satellite-detected hotspots, indicating a strong heat source from active fires.

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CALIPSO LIDAR was used to help further investigate the transport of smoke from these fires. The LIDAR shows the height of the clouds that were produced by these fires. The first image is the 532 nm Total Attenuated Backscatter plot on 22 May from 20:04 UTC to 20:17 UTC. The smoke from these fires can be seen around 57 N and 55 N, indicated by light grey pixels. This LIDAR was able to detect the smoke right above the fires. The next image is the Depolarization plot, on this plot the smoke is indicated by orange pixels. The third image is the 1064 nm Total Attenuated Backscatter plot, the smoke on this plot is indicated by a light grey color. The fourth image is the Attenuated Ratio plot between 1064 nm and 532 nm. The smoke is indicated by teal and purple pixels. The fifth image is the Vertical Feature Mask. This plot shows the different features that are in the atmosphere, the smoke is attributed as a cloud on this plot and is indicated by a light blue color. The last image shows the different subtypes of aerosols that are detected by the LIDAR. On this plot the smoke can be seen in a column (indicated by black color) around 56 N. This information proves that there is a fire around 56 N producing smoke, this is is conclusive with the coordinates that produced a pyroCb.

CALIPSO 532 nm Total Attenuated Backscatter on 22 May (click to enlarge)

CALIPSO 532 nm Total Attenuated Backscatter on 22 May (click to enlarge)

CALIPSO Depolarization Ration on 22 May (click to enlarge)

CALIPSO Depolarization Ration on 22 May (click to enlarge)

CALIPSO 1064 nm Total Attenuated Backscatter on 22 May (click to enlarge)

CALIPSO 1064 nm Total Attenuated Backscatter on 22 May (click to enlarge)

CALIPSO Attenuated Color Ratio between 1064 nm and 532 nm on 22 May (click to enlarge image)

CALIPSO Attenuated Color Ratio between 1064 nm and 532 nm on 22 May (click to enlarge image)

CALIPSO Vertical Feature Mask on 22 May (click to enlarge image)

CALIPSO Vertical Feature Mask on 22 May (click to enlarge image)

CALIPSO Aerosol Subtype plot on 22 May (click to enlarge image)

CALIPSO Aerosol Subtype plot on 22 May (click to enlarge image)

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