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

Another PyroCb in Cecil Plains

Another pyroCb formed on 06 December in Cecil Plains in Queensland, Australia. Starting at 4:00 UTC on 06 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 (~28.2º S, 151ºE) formed around 7:50 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 4:00 UTC on 06 December, shows that the brightness temperature for the pyroCb cloud reached roughly -66ºC at 5:40 UTC (dark red 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)

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 -24º C at 4:33 UTC which is an hour before the coldest brightness temperature of -66º C found on Himawari.

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

PyroCb in Cecil Plains

Towards sunset a pyroCb formed in Cecil Plains in Queensland, Australia. Starting at 7:00 UTC on 05 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 (~28.2º S, 151ºE) formed around 7:50 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 7:00 UTC on 05 December, shows that the brightness temperature for the pyroCb cloud reached roughly -59ºC at 9:10 UTC (red 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)

1-km resolution POES AVHRR images (below; courtesy of René Servranckx) showed pyroCb cloud-top IR brightness temperatures as cold as -66.6º C at 8:39 UTC.

POES AVHRR Shortwave Infrared (left) and Infrared Window (right)

PyroCb in Australia

Suomi NPP VIIRS true-color image at 04:16 UTC on 04 December 2016 (click to enlarge)

Suomi NPP VIIRS true-color image at 04:16 UTC on 04 December 2016 (click to enlarge)

On 04 December 2016 a pyroCb developed to the west of Toowoomba in Queensland, Australia. A Suomi NPP VIIRS true-color image around 04:16 UTC (above) showed the early stage of the smoke plume in the Cecil Plains area, about 2 hours prior to the pyroCb formation.

Himawari-8 monitored the temporal evolution of the smoke plumes and pyroCb cloud, as well as the fire hot spots. Starting at 5:00 UTC on 04 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 (~27.5º S, 151.4ºE) formed around 6:00 UTC. In the shortwave IR images, the red pixels indicate very hot IR brightness temperatures exhibited by the fire source regions. Also note the characteristic warmer (darker gray) appearance of the pyroCb cloud on the shortwave IR images, compared to the larger meteorological cumulonimbus cloud that developed just to the south of the fire.

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 5:00 UTC on 04 December, shows that the brightness temperature for the pyroCb cloud reached roughly -60ºC at 6:50 UTC (red 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)

CALIOP data from a CALIPSO satellite overpass on 05 December (below) captured the signature of the young pyroCb smoke plume aloft along the east coast of Australia. The feature is located above the cursor in each image, at an altitude of 12-13 km; note that the Depolarization Ratio values are very low (ruling out a typical cloud feature), and the Feature Mask flags it as Aerosol (orange).

CALIPSO CALIOP Total Attenuated Backscatter (click to enlarge)

CALIPSO CALIOP Total Attenuated Backscatter (click to enlarge)

CALIPSO CALIOP Depolarization Ratio (click to enlarge)

CALIPSO CALIOP Depolarization Ratio (click to enlarge)

CALIPSO CALIOP Feature Mask (click to enlarge)

CALIPSO CALIOP Feature Mask (click to enlarge)

For a surface perspective to compliment the satellite imagery, a few storm chasers took some great photos of the pyroCb. These pictures (courtesy of Nicholas McCarthy) show the large smoke columns that result in the formation of these pyroCb clouds. The first picture below shows the smoke from the wildfire rising up and forming these clouds with large vertical extent.

cecilplainspyrocb4
cecilplainspyrocb3
cecilplainspyrocb1

cecilplainspyrocb2

PyroCb in Russia

On 19 September 2016 a pyroCb formed northwest of Lake Baikal in eastern Russia. Himawari-8 detected the smoke plumes and pyroCb cloud, as well as the fire hot spots. The pyroCb cloud (~57.4º N, 105.3ºE) formed around 8:20 UTC . Starting at 7:30 UTC on 19 September, the animation below (also available as an MP4) 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 8:00 UTC on 19 September, shows the brightness temperature for the pyroCb cloud reached -36.9ºC at 9:10 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 slightly longer animation — covering the period from 06:00 to 09:20 UTC — 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 northeastward.

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]

The coldest IR brightness temperature on a 12:12 UTC Metop-B image (below, courtesy of Rene Servranckx) was -45.3 C.

Metop-B AVHRR Shortwave Infrared (left) and Longwave Infrared (right) images at 12:12 UTC [click to enlarge]

Metop-B AVHRR Shortwave Infrared (left) and Longwave Infrared (right) images at 12:12 UTC [click to enlarge]

Suomi NPP OMPS Aerosol Index images (courtesy of Colin Seftor) show the transport of smoke on 20 September . The maximum AI was found to be 11.9 at 59.23 N 108.9 E around 4:48 UTC. This is northeast of the original pyroCu and is consistent with the movement of the smoke and pyroCb cloud seen in the animations above.

OMPS Aerosol Index image on 20 September

OMPS Aerosol Index image on 20 September

A close-up view of the dense smoke pall on 19 September — which was entrained into the circulation of a compact middle-tropospheric (500 hPa) low pressure / enhanced vorticity lobe that was passing over the area of active fires — as seen on a Suomi NPP VIIRS true-color image (with VIIRS-detected fire hot spots in red) is shown below. There was also a compact 500 hPa cold pool of -20º C associated with this low/vorticity feature, which help to destabilize the atmosphere making the environment more conducive to pyroCb development.

Suomi NPP VIIRS true-color image + VIIRS-detected fire hot spots [click to enlarge]

Suomi NPP VIIRS true-color image + VIIRS-detected fire hot spots [click to enlarge]

A sequence of daily VIIRS true-color images during the 13-18 September period showed the increase in areal coverage of smoke across that region as fire activity ramped up (below).

Suomi NPP VIIRS true-color images during the 13-18 September period [click to enlarge]

Suomi NPP VIIRS true-color images during the 13-18 September period [click to enlarge]