Wildfires in Warming Siberia: Trends, Transportation and Implications on Arctic Climate

Wildfires in carbon-rich northern high latitudes, especially Siberia, is an important phenomenon because it can worsen the air quality and accelerate warming over the Pan-Arctic regions. We investigate the shift of wildfire regimes in northern high latitudes over the recent decades using Moderate Resolution Imaging Spectroradiometer (MODIS) active fire data. Northeast Siberia has experienced a significant increase in the number of wildfires (+11.04 % year^-1) and the mean period of events (+0.16 days year^-1). Strengthened anomalous anti-cyclonic circulation from the surface to the upper troposphere over Northeast Siberia under the Pan-Arctic warming is responsible for more active wildfires over the last decades. This causes strong and long-lasting warm and dry conditions conducive to the ignition and persistence of wildfire. Additionally, extreme wildfire events in Northeast Siberia show that biomass-burning aerosols and gases are transported into the Arctic Ocean, contributing to the rapid melting of sea ice and snow by altering the surface radiation budget. These results suggest that extended wildfire activities in Northeast Siberia are critical to predicting the future Arctic climate.