Anomalous Wildfires in Siberia in Summer 2019

Wildfires as a Source of PAHs in Surface Waters of Background Areas (Lake Baikal, Russia)

“…The calculations of back trajectories of air mass transport using the HYSPLIT model and satellite imagery for this period (Figure 4) confirms the transport of smokes from fires to the water area of the southern part of Lake Baikal and, hence, the source of the extreme ƩPAH concentrations in the aerosol and the upper water layer of the pelagic zone of the southern basin in 2016. In May 2019, wildfires in the north of the Irkutsk Region were recorded in an area of 8600 km 2 , whereas in July, the areas of fires reached 28,000 km 2 (Figure 5a), and in September, they decreased to 1700 km 2 [18]. The calculation of back trajectories of air mass transport (Figure 5b) testified to the possibility of combustion products entering the water area of the northern basin of Lake Baikal.…”

“…Obviously, the change in the ratio of individual PAHs is associated with the influx of pollutants from different sources. In this context, the 2016 data on the southern basin can be associated with the local transport of the smoke from wildfires that took place in that season on the coast of the lake, whereas an increase in the PAH concentrations in the water of the northern basin in 2019 due to light naphthalenes-with the long-range atmospheric transport of the wildfire smoke from the northern areas of the Baikal natural territory [18,56].…”

“…wildfires in the adjacent areas of the water area of Lake Baikal. These seasons [18] were distinguished by the most severe wildfires. In July 2016, the fires were recorded in an area of 28,100 km 2 , and in September, they were recorded in an area of 14,100 km 2 .…”

“…An increase in the PAH concentrations in the upper water layer of the pelagic zone of the lake in 2016 and 2019 can be explained as a result of the impact of plumes from wildfires in the adjacent areas of the water area of Lake Baikal. These seasons [18] were distinguished by the most severe wildfires. In July 2016, the fires were recorded in an area of 28,100 km 2 , and in September, they were recorded in an area of 14,100 km 2 .…”

“…From 2015 to 2019, fires engulfed forests in areas of 62,500, 79,500, 44,400, 36,100, and 72,400 km 2 , respectively. In 2019, fires in East Siberia were considered a global environmental disaster: forests in an area of up to 72,400 km 2 were engulfed in fire; the volumes of emissions of carbon dioxide and fine РМ 2.5 aerosol were ≈46 and ≈0.39, respectively [18]. During forest burning, not only carbon dioxide is released into the atmosphere but also persistent organic pollutants (POPs) that include polycyclic aromatic hydrocarbons (PAHs) as the main components.…”