07 February 2008

Australia Bushfire Activity: 11-30 Jan 2008

Below are shown the previous two 10-day hotspot composite maps for Australia from the NASA Rapid Response Global Fire Maps page. The dates are 11-20 January and 21-30 January.

Overall, the previous 3 weeks or so have seen relatively little fire activity. Compared to the same time last year (11-20 Jan), fire activity in the eastern portion of the country is *greatly* reduced, while fire activity in NW WA (Pilbara) is greater. Climate-wise, the reduction in fire activity in the east is typical behaviour of a moderate-to-strong La Nina. This continues a trend from the previous national update.

During the first period, major fires were noted in Tasmania and WA. In Tasmania, major bushfires were reported in the northeast portion of the state: west of St Helens and another near Bellingham. In SW WA, a large bushfire was reported in Fitzgerald River National Park near Hopetoun. It was initially started by lightning and burned in excess of 40 000 ha. In VIC, the fire near Ballarat noted here earlier is visible.

During the second period, the eastern Australia as a whole has been relatively quiet. There is an apparent small increase in the number of hotspots detected in SE QLD. It is unclear with this data as to whether this is due to a decrease in general cloud cover over the region during the second period or a real phenomenon. Regardless, any activity seems relatively insignificant. A few fires have been reported is TAS, as well. In southern WA, a large fire not noted by the media in the national parks to the west of Albany. Hotspots first noted on 24th, but the fire burned fiercely on the 27th, judging by the smoke plume in the MODIS image for the day.

The peak region of fire activity is found in a broad swath of WA extended from the NT border across to the Pilbara. During the second period, fire activity is seen extending down in the the Great Sandy Desert region as well. Most of this fire activity is sporadic. Small fires (small for the north, anyway...) which last for two or three days before extinguishing. Reviewing the MODIS subsets shows that there were several distinct periods when fire behaviour was observed. Early in the first period (10-14 Jan), fires were quite numerous throughout the Pilbara. Fire activity then was greatly reduced for 4 or 5 days, gradually become more widespread starting the desert regions and extending westward and southward. The second period has seen several days of activity, but in the Pilbara, this fire activity stopped around the 30th.

The La Nina looks set to continue for the next several months. In general, this sort-of low level behaviour should continue. Tasmania in particular remains dry, as does SA. Parts of VIC have seen above-average rainfall during January, but much of this fell on one day...there is still the potential for significant fire activity in all of these regions.