Krasnoyarsk scientists have shown that smoke from forest fires can not only cause air pollution, but can also lead to a decrease in the temperature of the ground layer of air and soil, and contribute to the formation of fogs over the Yenisei. The results of the study were published in the journal Environmental Processes.

Every year, thousands of forest fires are recorded in Russia, whose area amounts to several million hectares, most of them occurring in the forests of the Siberian and Far Eastern regions. Since the end of the 20th century, the frequency and area of forest fires in Siberia have approximately doubled compared to the previous decade. At the same time, climate change could lead to a doubling of the number of fires in boreal forests by the end of this century, increasing their impact on the environment.

Researchers from the Krasnoyarsk Science Center of SB RAS draw attention to the fact that smoke in the area caused by forest fires can lead to screening of solar radiation and, accordingly, cooling of the Earth’s surface - the so-called “nuclear winter effect.”

In the summer of 2021, there occurred large-scale forest fires in Yakutia. Their area, according to remote monitoring data from Rosleskhoz, became the largest recorded since the beginning of the century. Smoke from these fires appeared in Krasnoyarsk on August 7, 2021 and remained in the city for three days. The specialists have found that during the smoke, the air concentration of particles 2.5 micrometers in size (PM2.5) increased more than tenfold. This reduced the ability of the atmosphere to transmit light, causing soil temperatures to drop by more than five degrees and ground atmospheric temperatures by almost two degrees Celsius. Cooling humid air created fog over the Yenisei River in Krasnoyarsk.

“Our goal was to analyze the extent of the impact of smoke from forest fires on the environment. The research was based on satellite data from Earth remote sensing, measurements of environmental parameters at monitoring posts in Krasnoyarsk and soil temperature in agricultural fields of the Minino experimental production farm of the Federal Research Center of the Kola Scientific Center SB RAS. Smoke from the fires led to a decrease in air and soil temperatures and to the formation of fog over the Yenisei. It is important to take into account the discovered phenomena when modeling and considering the consequences of air pollution in the city,” said Oleg Yakubailik, Candidate of Physical and Mathematical Sciences, Deputy Director of the Institute of Computational Modeling of SB RAS.