Lightning-Ignited Wildfires beyond the Polar Circle

• Published in: Atmosphere Vol. 14; no. 6; p. 957
• Main Authors: Kharuk, Viacheslav I., Dvinskaya, Maria L., Golyukov, Alexey S., Im, Sergei T., Stalmak, Anastasia V.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2023
• Subjects: Air temperature; arctic fires; arctic vegetation productivity; Burning; Burning rate; Carbon; Carbon sinks; Causes of; Climatic changes; Correlation analysis; Environmental aspects; Fires; Forest & brush fires; Heat waves; Heatwaves; Influence; Lightning; lightning fire ignition; Lightning frequencies; MODIS; Moisture content; Moisture effects; northward fire migration; Owls; Precipitation (Meteorology); Productivity; Satellites; Soil moisture; Soil temperature; Taiga & tundra; Temperature extremes; Trends; Vegetation; Vegetation dynamics; Water content; wildfire recovery; Wildfires; Russia; Canada; Arctic region; Yenisei River; Siberia; Scandinavia; Greenland
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos14060957

Warming-driven lightning frequency increases may influence the burning rate within the circumpolar Arctic and influence vegetation productivity (GPP). We considered wildfire occurrence within the different Arctic sectors (Russian, North American, and Scandinavian). We used satellite-derived (MODIS) data to document changes in the occurrence and geographic extent of wildfires and vegetation productivity. Correlation analysis was used to determine environmental variables (lightning occurrence, air temperature, precipitation, soil and terrestrial moisture content) associated with a change in wildfires. Within the Arctic, the majority (>75%) of wildfires occurred in Russia (and ca. 65% in Eastern Siberia). We found that lightning occurrence increase and moisture are primary factors that meditate the fire frequency in the Arctic. Throughout the Arctic, warming-driven lightning influences fire occurrence observed mainly in Eastern Siberia (>40% of explained variance). Similar values (ca. 40%) at the scale of Eurasia and the entire Arctic are attributed to Eastern Siberia input. Driving by increased lightning and warming, the fires’ occurrence boundary is shifting northward and already reached the Arctic Ocean coast in Eastern Siberia. The boundary’s extreme shifts synchronized with air temperature extremes (heat waves). Despite the increased burning rate, vegetation productivity rapidly (5–10 y) recovered to pre-fire levels within burns. Together with increasing GPP trends throughout the Arctic, that may offset fires-caused carbon release and maintain the status of the Arctic as a carbon sink.