CIMSSPyroCb

Fires in eastern Russia and Mongolia

MTSAT-2 0.68 µm visible channel (left) and 3.75 µm shortwave IR channel (right) images [click to play animation]
MTSAT-2 0.68 µm visible channel (left) and 3.75 µm shortwave IR channel (right) images [click to play animation]
MTSAT-2 0.68 µm visible channel and 3.75 µm shortwave IR channel images (above; click image to play animation) showed that numerous wildfires had developed over far southeastern Russia (near the Russia/Mongolia/China border) during the day on 29 March 2014. A portion of Lake Baikal is outlined in blue in the far upper left corner of the images; the largest of the still-frozen lakes seen in the lower center portion of the images was Hulun Lake in far northeastern China. The only regularly-reporting surface station in the area was Chita, Russia (station identifier UIAA) – note the sharp drop in dew point temperatures during the day, falling from +18º F (-7.8º C) at 22 UTC on 27 March to -4º F (-20.0º C) at 05 UTC on 28 March. This sharp drop in dew point was accompanied by westerly to northwesterly winds with sustained speeds of 20 knots (10.3 meters per second).

The corresponding MTSAT-2 10.8 µm IR channel images (below; click image to play animation) revealed that the large cluster of fires southeast of Chita generated a pyroCumulonimbus (pyroCb) cloud shortly before 09:32 UTC; the minimum IR brightness temperature of this pyroCb cloud was -46.6º C (lighter yellow color enhancement) at 10:32 UTC. However, the pyroCb cloud top IR brightness temperatures then began to rapidly warm after 11:32 UTC.

MTSAT-2 10.8 µm IR channel images [click to play animation]
MTSAT-2 10.8 µm IR channel images [click to play animation]
 

Large bushfires in southeastern Australia

MTSAT-2 0.68 µm visible channel (left) and 3.75 µm shortwave IR (right) images [click to play animation]
MTSAT-2 0.68 µm visible channel (left) and 3.75 µm shortwave IR (right) images [click to play animation]
An extended period of hot, dry weather led to the development of multiple large bushfires across parts of southeastern Australia, some of which began to produce pyrocumulonimbus (pyroCb) clouds during the 15-16 January 2014 period. McIDAS images of MTSAT-2 0.68 µm visible channel and 3.75 µm shortwave IR channel data (above; click image to play animation; also available as an MP4 animation) showed the development of a well-defined pyroCb associated with the Northern Grampions fire in the state of Victoria. After the visible images on the left panels faded to black during the night-time hours, the shortwave IR images on the right panels showed that many of the fire “hot spots” (denoted by the darker black pixels) continued to grow during the night.

MTSAT-2 10.8 µm longwave IR channel images (below; click image to play animation; also available as an MP4 animation) indicated that cloud-top IR brightness temperatures associated with the rapidly-growing pyroCb cloud became as cold as -38.7º C (lighter green color enhancement) at 07:32 UTC. Other areas of cold-topped thunderstorms developed near the coast, likely initiated by sea breeze and/or local terrain influences. Surface reports ploted on the IR images revealed very hot temperatures: for example, it was 109º F (42.8º C) at Melbourne Essondon (station identifier YMEN) at 04 UTC.

MTSAT-2 10.8 µm longwave IR images [click to play animation]
MTSAT-2 10.8 µm longwave IR images [click to play animation]
A larger-scale view of MTSAT-2 0.68 µm visible channel images (below, visualized using the SSEC RealEarth web map server) showed that there were also some large bushfires to the northwest that were producing long, dense smoke plumes which were drifting southward off the coast.

MTSAT-2 0.68 µm visible channel images [click to play animation]
MTSAT-2 0.68 µm visible channel images [click to play animation]
 

Bush fires in the Sydney, Australia region

Update 10/21/13:

While there’s still no clear indication of pyroconvection from the MTSAT imagery, the Sydney fires have continued to burn over the weekend, belching large quantities of smoke over the western Pacific. The MTSAT-2 visible and shortwave infrared loop (below; click image to play animation) contains hourly images from 00:32UTC on Oct. 17 to 16:32UTC on Oct. 21. While the temporal resolution of the MTSAT-2 imagery over this region is somewhat coarse (hourly images instead of 30 or 15 minute images), it is still possible to see the time evolution of these fires (dark black pixels) in the infrared imagery and their smoke emission in the visible imagery. While it is possible that some brief pyroconvection may have been missed due to the lack of imagery, it is unlikely that a full pyrocumulonimbus formed and decayed entirely in an hour.

MTSAT-2 visible channel (left) and shortwave IR channel (right) images (click to play animation)
MTSAT-2 visible channel (left) and shortwave IR channel (right) images (click to play animation)

The  Aqua MODIS 250m true color imagery from Oct. 21 offers a better view of the sizable smoke plumes being created by these fires.

Aqua MODIS true color image
Aqua MODIS true color image

According to CNN, there is concern in the Sydney region that these bush fires may conglomerate into one large complex, further threatening the populous New South Wales region. In the case of such an amalgamation, this region would additionally be well-primed for pyroconvection; more updates will come as these fires evolve.

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Original Post:

MTSAT-2 visible channel (left) and shortwave IR channel (right) images (click to play animation)
MTSAT-2 visible channel (left) and shortwave IR channel (right) images (click to play animation)

Numerous bush fires began to burn in state of New South Wales near Sydney, Australia on 16-17 October 2013. On a comparison of MTSAT-2 visible channel and shortwave IR channel images (above; click image to play animation) some of the southeastward-drifting smoke plumes were evident on the visible images, while numerous fire “hot spots” (darker black pixels) could be seen on the shortwave IR images. Toward the end of the animation (at 06:32 UTC on 17 October), the hot fire pixels grew in areal coverage as winds increased in association with a cold frontal passage. Sydney (station identifier YSSY) is at the center of the images.

A 48-hour plot of surface data for Sydney Airport (below) showed that smoke restricted the surface visibility to 4-5 miles from 02-06 UTC on 17 October. Prior to the passage of the cold front, surface air temperatures were unseasonably hot (in the middle 90s F), with wind gusts as high as 38 knots. In addition, note the sharp drop in dew point temperature to -2º F at 04 UTC on 17 October.

Plot of surface data for Sydney, Australia
Plot of surface data for Sydney, Australia

A 250-meter resolution Aqua MODIS true color image from the NASA EOSDIS Worldview site (below) offers a closer view of the smoke plumes in the Sydney area.

Aqua MODIS true color image
Aqua MODIS true color image

PyroCb Event in British Columbia, Canada

GOES-15 Visible and Shortwave IR images (Click image to play animation)
GOES-15 Visible and Shortwave IR images (Click image to play animation)

On 15 September 2013, a Pyrocumulonimbus (PyroCb) was detected by GOES-15 imagery in British Columbia, Canada in the center of the province. The animation above is imagery from GOES-15 (click animation to play); the panel on the left is the visible bandwidth and the panel of the right is shortwave infrared bandwidth highlighting the fire hot-spots in black and red pixels. The PryoCb began at 23:30 UTC and continues for the next few hours until 02:30 UTC on 16 September 2013.

GOES-15 Longwave IR (Click image to play animation)
GOES-15 Longwave IR (Click image to play animation)

Using the GOES-15 Longwave IR imagery (above, click image to play animation), we were able to see the cloud-top temperatures associated with the PyroCb in the center of image (Latitude: 54 N, Longitude: 126 W) become colder than -40 ˚C  (green color enhancement) after 23:30 UTC and continues until 02:30 UTC. The higher the clouds are, the colder the cloud top temperatures. This PyroCb gets as cold as -55˚C, which is quite impressive for a PyroCb to reach this height in the atmosphere.