PyroCb in Utah

On 22 June 2017 a pyroCb formed from the Brian Head Fire in Utah. GOES-15 detected the smoke plumes and pyroCb cloud, as well as the fire hot spot. The pyroCb cloud (~37.7º N, 112.8ºW) formed around 23:30 UTC . Starting at 23:00 UTC on 21 June, 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)

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 data is used to analyze the cloud-top IR brightness temperatures. However, due to the 4-km resolution of the satellite the brightness temperature never reached the -40ºC threshold.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 -42.7º C (light blue color enhancement) for the pyroCb.

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)

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)

Suomi NPP OMPS Aerosol Index images (courtesy of Colin Seftor) shows the transport of smoke on 22 June . This max AI was 6.4 at 37.8 N 112.4 W at 20:38 UTC. This is near the source of the pyroCb.

OMPS Aerosol Index image on 23 June

OMPS Aerosol Index image on 22 June

PyroCb in Yukon

On 19 June 2017 a pyroCb formed in Yukon. GOES-15 detected the smoke plumes and pyroCb cloud, as well as the fires hot spot. The pyroCb cloud (~66º N, 137ºW) formed around 23:30 UTC . Starting at 22:00 UTC on 19 June, 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)

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

In addition, using GOES-15 10.7 μm IR channel the cloud-top IR brightness temperature could be found. The animation below, starting at 3:00 UTC on 20 June, shows the brightness temperature for the pyroCb cloud reaching near  -47ºC at 5 UTC (green color enhancement).

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

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

Suomi NPP OMPS Aerosol Index images (courtesy of Colin Seftor) shows the transport of smoke on 20 June . This max AI was 5.3 at 66 N 142.7 W at 23:06 UTC. This is west of the pyroCb.

OMPS Aerosol Index image on 20 June

OMPS Aerosol Index image on 20 June

Two PyroCbs in Russia

On 12 June 2017 two pyroCbs formed northwest of Lake Baikal in eastern Russia. Himawari-8 detected these smoke plumes and pyroCbs cloud, as well as the fires hot spots. The first pyroCb cloud (~54.3º N, 105.7ºE) formed around 9:20 UTC . The second pyroCb cloud (~55.4º N, 107.4ºE) formed around 10:50 UTC. Starting at 9:00 UTC on 12 June, 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.

HIMAWARI-8 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)

HIMAWARI-8 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)

 

In addition, using Himawari-8 10.4 μm IR channel the cloud-top IR brightness temperature could be found. The animation below, starting at 10:30 UTC on 12 June, shows the brightness temperature for the first pyroCb cloud reaching near  -60ºC. The image below indicates the minimum brightness temperature to be -60.2ºC at 13:48 UTC. This is far later than the loop. The second pyroCb reaches a minimum brightness temperature at 11:02 UTC (green color enhancement).

HIMAWARI-8 10.4 µm IR channel images (click to play animation)

HIMAWARI-8 10.4 µm IR channel images (click to play animation)

 

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 -60.2º C (red color enhancement) for the first pyroCb and -44.9º C for the second (green color enhancement) .

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) [click to enlarge]

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)

PyroCb in Russia

Himawari-8 0.64 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.4 µm Longwave Infrared Window (bottom) images [click to play animation]

Himawari-8 0.64 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.4 µm Longwave Infrared Window (bottom) images [click to play animation]

Himawari-8 Visible (0.64 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) images (above) showed a wildfire burning in Russia on 25 May 2017 at 58.3N 106.2E. This fire reached a minimum brightness temperature around -40ºC around 8:30 UTC.

Suomi NPP OMPS Aerosol Index images (courtesy of Colin Seftor) shows the transport of smoke on 25 May . This max AI was near the source of the pyroCb.

OMPS Aerosol Index image on 25 May

OMPS Aerosol Index image on 25 May

1-km resolution POES AVHRR images (below; courtesy of René Servranckx) showed pyroCb cloud-top IR brightness temperatures right before the major development of the pyroCb. The coldest brightness temperature was -49.5º C at 7:45 UTC.

POES AVHRR Visible (upper left), Shortwave Infrared (upper right), Infrared Window (lower left) and false-color RGB (lower right) images

POES AVHRR Visible (upper left), Shortwave Infrared (upper right), Infrared Window (lower left) and false-color RGB (lower right) images

Sir Ivan Fire pyroCb in New South Wales, Australia

Himawari-8 0.64 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.4 µm Longwave Infrared Window (bottom) images [click to play animation]

Himawari-8 0.64 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.4 µm Longwave Infrared Window (bottom) images [click to play animation]

Himawari-8 Visible (0.64 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) images (above / MP4 ; zoomed-in over fire source region: GIF / MP4) showed wildfires burning in New South Wales, Australia on 12 February 2017. The larger Sir Ivan fire near Dunedoo produced a pyroCb cloud, which first cooled below the Longwave Infrared brightness temperature threshold of -40ºC at 0530 UTC (-47ºC) and quickly reached its minimum temperature of -56.6ºC at 0540 UTC. According to the Melbourne rawinsonde data (plot | text), this temperature corresponded to an altitude of nearly 14 km. An animation of  Himawari-8 true-color images is available here (courtesey of Dan Lindsey).

Consecutive true-color images from Suomi NPP VIIRS (0402 UTC) and Aqua MODIS (0405 UTC) viewed using RealEarth (below) showed the large smoke plume about 1.5 hours prior to pyroCb development.

Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]

Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]


A high fire danger was well-anticipated across this portion of Australia:

Some ground-based photos of the pyroCb cloud:

 

 

Suomi NPP OMPS Aerosol Index images (courtesy of Colin Seftor) shows the transport of smoke on 12 February . The maximum AI was found to be 9.3 at 32.6 S 150.9 E around 4:02 UTC. This max AI is near the source of the pyroCb.

OMPS Aerosol Index image on 12 February

OMPS Aerosol Index image on 12 February

Cocklebiddy Fire PyroCb in Australia

A slightly longer animation — covering the period from 20:40 on 6 December to 09:40 UTC on 7 December — of Himawari-8 Visible (0.64 μm), Shortwave Infrared (3.9 μm) and Infrared Window (10.4 μm) images is shown below. The pyroCb cloud formed near the center of the images, and the cold anvil of the cloud then moved rapidly southeast. The pyroCb reached brightness temperatures of -60ºC (red color enhancement) around 4:50 UTC.

Himawari-8 Visible (top), Shortwave Infrared (middle) and Infrared Window (bottom) images [click to play animation]

Himawari-8 Visible (top), Shortwave Infrared (middle) and Infrared Window (bottom) images [click to play animation]

Starting at 0:00 UTC on 07 December, the animation below (also available as an MP4) shows Himawari-8 0.63 µm visible (left) and 3.9 µm shortwave IR (right) . The pyroCb cloud (~32.1º S, 126.1ºE) formed around 2:30 UTC. In the shortwave IR images, the red pixels indicate very hot IR brightness temperatures exhibited by the fire source regions.

Himawari-8 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)

Himawari-8 0.63 µm visible channel (left) and 3.9 µm shortwave IR channel images (right) (click to play animation)

In addition, the Himawari-8 10.4 μm IR channel allowed the cloud-top IR brightness temperature to be measured. The animation below, also starting at 1:00 UTC on 07 December, this animation did not capture the lowest brightness temperatures. However, this animation shows the progression of brightness temperatures near the pyroCb source.

Himawari-8 10.4 µm IR channel images (click to play animation)

Himawari-8 10.4 µm IR channel images (click to play animation)

The image below (courtesy of Colin Seftor) shows on the left the pyroCb from VIIRS and on the right the OMPS AI Index. The maximum AI values are only about 3 which is rather low.

Left VIIRS image and right OMPS AI Index