Smoke from bushfires in south-eastern Australia has been detected over Antarctica for the first time since the 2019-20 black summer fires.
Scientists detected the smoke particles at the Profesor Julio Escudero Base, a Chilean research station on King George Island, at the northern tip of the Antarctic peninsula.
The smoke signal was first discovered on 21 December and was present the following week, including a detection on Sunday, the latest day for which data was available. The particles were at a height of at least 5km up in the atmosphere.
Bushfires in the Grampians national park in Victoria have burned through more than 76,000 hectares of land and destroyed at least three homes. The fires continue to burn, although firefighters say conditions have eased. A separate fire in Western Australia also burned through more than 3,200 hectares of land.
Dr Raúl Cordero of the University of Groningen, whose team runs Escudero Base, said that once it falls to ground, black carbon from bushfire smoke may increase snowmelt on Antarctica.
“It’s going to eventually make the snow darker, and by doing so, it’s going to contribute to accelerating the melting of the snow.”
This was because darker snow absorbs more energy in the form of solar radiation.
Cordero’s research has previously found that, based on samples taken between 2016 and 2020, black carbon pollution from Antarctic tourism and research activities was probably increasing snowmelt by an estimated 83 tonnes a visitor.
“The particles produced by fires have exactly the same effect on the snow as particles produced by the combustion of diesel … for powering ships,” Cordero said.
The smoke was picked up on a ground-based photometer associated with Nasa’s aeronet robotic network. The tool measures solar radiation and the amount that is absorbed by black carbon particles in the atmosphere.
“The instruments allow us to detect not only the presence of particles but also the type of particles,” Cordero said. “We are reasonably sure the source of this smoke is the active fire system covering Australia.”
“The amount of particles we are talking about is still relatively small,” Cordero said, adding that the smoke over Antarctica was not concentrated enough to be detected by satellites.
The smoke was detected on the Antarctic peninsula, where about half of the continent’s research facilities are located and where about 95% of tourist trips are made.
Black carbon in the air was also detected at Marambio, an Argentinian research base about 200km from the Chilean station.
“This is an additional source of pollution that is going to add to the anthropogenic signal that is making Antarctica a little bit darker,” Cordero said.
Last season there were 122,000 tourist visitors to Antarctica, a figure that has tripled in the last decade.
