Black summer bushfires may have caused rare ‘triple dip’ La Nina, study suggests
(The Guardian, 10 May 2023) Smoke aerosols from the fires interacted with clouds to cool the south-eastern Pacific, helping the wet weather pattern to form.
Smoke from Australia’s 2019-20 black summer fires may have resulted in the rare “triple dip” La Niña that lasted from 2020 to 2022, research suggests.
Modelling from scientists at the US National Center for Atmospheric Research has found that smoke aerosols from the bushfires interacted with clouds to cool surface waters over the south-eastern subtropical Pacific Ocean.
This created favourable conditions for a La Niña to form, the researchers believe.
The research, published in the journal Science Advances, could be used to improve climate cycle predictions in future.
The study’s first author, Dr John Fasullo of the National Center for Atmospheric Research, said although the bushfire smoke only persisted in the atmosphere for several months, it triggered a long-lasting feedback loop. “We did not expect such a strong planetary-scale signature with these fires,” he said.