Yan Yu1,2* and Paul Ginoux3
1Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
2Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
3NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA
*Correspondence to Yan Yu (yuyan@pku.edu.cn)
Abstract
Large wildfires reduce vegetation cover and soil moisture, leaving the temporally degraded landscapes an emergent source of dust emission. However, the global extent of post-fire dust events and their influencing factors remain unexplored. Using satellite measurements of active fires, aerosol abundance, vegetation cover and soil moisture from 2003 to 2020, here we show that 54% of the examined ~150,000 global large wildfires are followed by enhanced dust emission, producing substantial dust loadings for days to weeks over normally dust-free regions. The occurrence and duration of post-fire dust emission is controlled primarily by the extent of precedent wildfires and resultant vegetation anomalies and modulated secondarily by pre-fire drought conditions. The intensifying wildfires and drying soils during the studying period have made post-fire dust events one day longer, especially over extratropical forests and grasslands. With the predicted intensification of regional wildfires and concurrent droughts in the upcoming decades, our results indicate a future enhancement of sequential fire and dust extremes and their societal and ecological impacts.
Key points
· Satellite measurements show that dust emission is enhanced following large wildfires, producing considerable dust loadings for days to weeks over normally dust-free regions.
· The occurrence and duration of post-fire dust emission is primarily controlled by the extent of the precedent wildfires and resultant vegetation anomalies, and are secondarily modulated by pre-fire drought conditions.
· These sequential fire and dust extremes will likely become more frequent and severe under global warming, having increased societal and ecological impacts.
Citation
Yu, Y., Ginoux, P. Enhanced dust emission following large wildfires due to vegetation disturbance. Nat. Geosci. (2022). https://doi.org/10.1038/s41561-022-01046-6
