Climate change: Australian bushfires linked to largest stratospheric warming recorded in three decades

 
Bushfires in southeastern Australia in 2019-2020 ejected smoke particles into the Earth's upper atmosphere, contributing to the highest temperatures in the lower stratosphere since the early 1990s. A paper reporting thatScientific ReportsWill be published in.

Australia's wildfires released millions of tons of smoke aerosols into the Earth's atmosphere.What was unusual was that a significant amount of smoke reached lower stratospheric heights starting at a height of about 15 kilometers above Australia.Around the same time, the lower stratosphere experienced several months of abnormally high temperatures (the highest since 1992-1993).

Lilly Damany Pearce and colleagues investigated whether smoke aerosols emitted by Australian bushfires contributed to stratospheric warming. Using data from the CALIPSO satellite and the Sumi National Polar Orbit Partnership satellite, Pearce et al. We also examined the aerosol concentrations recorded by the two satellites in December. Pearce et al. reported the first smoke plume reaching an altitude of 2019 kilometers on 12 December 2020, and detected a similar plume on 2012 January 6.Smoke aerosols eventually reached altitudes of 2018-12 kilometers and were detected throughout 2.

Pearce et al. then applied their findings to the UK Earth System Model Version 1 (UKESM1) to estimate the effect of these smoke plumes on lower stratospheric temperatures.They then modeled the effects of smoke aerosols, changes in the ozone layer, or a combination of both on stratospheric temperature and compared them with control simulations of current climate.In smoke aerosol and ozone simulations, modeled temperatures for the lower stratosphere from January to June 2020 were significantly higher compared to present-day climate.A stratospheric warming of about 1°C was modeled for November 6 to March 2019, which was close to the 11°C spike observed during the same period.This suggests that forest fire smoke aerosols are responsible for stratospheric warming in the model, the authors say.The authors believe that the modeled abrupt warming is the largest since the 2020 eruption of Mount Pinatubo, which released sulfate plume aerosols into the stratosphere.

Pearce et al. suggest that climate change is projected to increase the frequency and intensity of future wildfires, so the probability of increased stratospheric warming and ozone depletion caused by smoke aerosols may increase. concludes.

 
* This article is reprinted from "Nature Japan Featured Highlights".
Reprinted from: "Climate change: 30-year record high stratospheric warming linked to Australian bushfires'