“The smoke is expected to make at least one full circuit around the globe, returning once again to the skies over Australia,” NASA said.
“Over the past week, NASA satellites have observed an extraordinary amount of smoke injected into the atmosphere from the Australian fires and its subsequent eastward dispersal.”
Bushfires have already burnt more than 5.2 million hectares in NSW and 1.3 million hectares in Victoria this fire season.
The smoke is having a dramatic impact on nearby New Zealand, which has experienced severe air quality issues and a darkening of the colour of the snow on the mountains.
NASA satellites show smoke has travelled more than 6500 kilometres away from Australia, with some of it reaching Chile, where hazy skies and colourful sunsets have been reported.
The space agency has also labelled Australia’s bushfire-generated storms, or pyrocumulonimbus events which have been exacerbating fire activity this week, as rare.
Mike Fromm of NASA’s Naval Research Laboratory said that by the agency’s measures, it was “the most extreme pyrocumulonimbus storm outbreak in Australia”.
A pyrocumulonimbus occurs when moisture trapped in the smoke condensed in the cold upper air produces a cloud, which then produces its own lightning.
“Large and numerous pyrocumulonimbus events are relatively rare — especially at this scale,” Chip Trepte, a project scientist from research body CALIPSO at NASA’s Langley Research Centre said.
The smoke has been tracked by satellite data used to create an ultraviolet aerosol index.
The UV index is particularly well suited to tracking smoke from pyrocumulonimbus events, according to NASA Goddard research scientist Colin Seftor, as the higher the smoke plume, the larger the aerosol index value.
“The aerosol index values produced by some of the Australian pyrocumulonimbus events have rivalled the largest values ever recorded,” he said.
Ashleigh McMillan is a breaking news reporter at The Age. Got a story? Email me at firstname.lastname@example.org