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.

________________________________________________________________________________________

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

Leave a Reply

Your email address will not be published.