06 November 2009

Barkly Tablelands NT

The image shows some several large bushfires burning in the Barklys Tableland, in central NT. The fires here, while burning for a week or so have flared, expanding a great deal in a short amount of time. On the true colour image, the smoke plumes from these fires are quite thick, suggesting vigorous fire activity.

Rather than the more typical true colour image, this is a so-called 721 image -- a different combination of channels from the MODIS. Green is vegetation. The recent burns scars are a dark brown colour, the very recent scars or even open fires are the bright red marks. The darker coloured scars are more recent; they get lighter brown to tan to back to green as a time passes, say 1-2 years. These do NOT have the hotspots marked...they show up quite well on their own with the red and pink.

The reason for the vigour of the fires is not immediately obvious. Weather conditions are not particularly severe; no fire weather warnings are in effect. More likely, the fires have reached an area of abundantly flammable (or is it flammabley abundant?) vegetation and taken off. There was some rain (and likely lightning activity) 4 or 5 days ago in the area, and this may nave been the igniter or reinforcer of these fires.

In general, bushfire has burnt much of the pictured area (about 220 x 390 km). The NAFI fire scars mapper indicates that most of this area burnt during October...looking thru old posts, much of it looks to have been quite recently...Indeed, fuel loads are quite high across the region as a result of abundant precipitation during the past wet season. The strengthening of the El Nino often results in a delayed onset of the wet season across the NT. This means that fire activity could extend further into the year, and perhaps even into January (if fuel is available)...

Finally, these fires are burning in a remote area and are of no threat to the usual concerns. The effects will mostly be on the ecology of the region, as well as a source of greenhouse gases in the atmosphere.

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