Cao, YF; Yin, MX; Tian, JX; Liang, SL (2024). Increased summertime wildfire as a major driver of the clear-sky dimming in the Siberian Arctic from 2000 to 2020. ATMOSPHERIC RESEARCH, 306, 107458.
Abstract
A warming Arctic is expected to exacerbate wildfires in Siberia, potentially creating a critical feedback to the Arctic climate change. However, our understanding of these fire -climate interactions remains limited. This study investigated changes in East Siberian wildfires and their influence on fire emissions, aerosol optical depth (AOD), and the surface clear -sky insolation across the Siberian Arctic from 2000 to 2020 using satellite observations. Our analysis reveals a substantial increase in wildfires, with fire counts doubling (a 114% increase) and fire radiative power surging by 8.4 x 10 6 MW compared to the early 21st century. Over 93% of this increase occurred during the boreal summer months. These intensified wildfires led to a significant rise in aerosol emission (organic carbon, PM2.5, and black carbon) exceeding 75% in East Siberia. Consequently, fire -season AOD in the Siberian Arctic increased by 33% (6.0 x 10 -2 ), with 85% (5.1 x 10 -2 ) attributable to wildfire changes. The wildfireassociated increase in AOD resulted in enhanced clear -sky dimming of 4.1 +/- 3.2 W m - 2 across the Siberian Arctic from 2000 to 2020. These findings suggest a critical feedback mechanism: a warming Arctic drives increased wildfires in Siberia, which in turn significantly impact the Arctic surface radiative budget through enhanced clear -sky dimming. Future simulations and projections for the Arctic should prioritize incorporating the feedback effects of intensifying wildfires.
DOI:
10.1016/j.atmosres.2024.107458
ISSN:
1873-2895