Last update: September 18th, 2019 at 6:00 pm
Dozens of fires were burning across northwestern Australia in late April 2016. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image on April 24.
Each red dot is a “hot spot” – an area where the thermal detectors on the MODIS instrument recognized temperatures higher than background. When accompanied by smoke, as in this image, such hot spots are diagnostic for actively burning fire.
The fires cluster in the savannah grasslands of Northern Territory and Western Australia, a typical pattern for this time of year. The hot, dry season typically begins in March in this part of Australia and follows a cooler, rainy season. The rainy season encourages lush plant growth which quickly becomes tinder-dry fuel in the dry season.
Most fires in this region are ignited by human activity, whether accidental or deliberate. A few deliberate ignitions are arson, but most are by people who use fire to manage the land. This may be for agriculture purposes (clearing land for pasture, cleaning up old crops, etc.) or it may be for fire suppression. Prescribed fires, which are deliberately set and then closely controlled, are commonly used in this area to reduce fuel load, and thus suppress the risk of bushfire as well as the intensity of any bushfire that may occur.
From this image, it is impossible to tell if these fires are agricultural in nature, are prescribed burns, or are bushfires. However, prescribed burning was occurring in parts of both the Northern Territory and Western Australia in late April, so it is likely that at least some of these fires are being managed as prescribed burns or for agriculture. It is also likely, however, that some are wild bushfires.