Exploration of the Meteorological Drivers of Extreme Wildfire Events in the Arctic during 2019–2020

Wildfire activities in the Arctic have increased in recent years, especially after the extraordinary explosions in 2019–2020. This study investigated the relationships between wildfire carbon emissions and meteorological factors in the key regions of the Arctic during 1997–2020, with the stepwise regression method using a series of meteorological variables (snowfall, precipitation, wind speed, relative humidity, 2-m air temperature, and daily maximum temperature) from MERRA-2 reanalyses and the Fire Weather Index (FWI). The authors further explored the dominant meteorological drivers for the large wildfires in the Arctic during 2019–2020. Results showed that in all three key regions, the Duff Moisture Code (DMC) from FWI makes the dominant contribution to wildfire emissions. The anomalously high geopotential height results in an extremely increased daily maximum temperature and significantly reduced precipitation, jointly leading to anomalously high DMC and consequent wildfire episodes during 2019–2020. This result suggests that climatic anomalies such as warming and drought promote frequent wildfire activities in the Arctic.