Unravelling spatiotemporal heterogeneity of wildfire carbon dioxide emissions in Southeast Asia: based on a high-resolution inventory.

Wildfire carbon dioxide emissions (FCE) profoundly impact the climate and environment. Land use, meteorology, and other factors contribute to the spatial heterogeneity of FCE. High-resolution emission inventories enhance our understanding of the spatiotemporal characteristics of emissions, providing critical data for climate change and environmental studies. In this study, we developed a 500-m resolution FCE inventory by integrating burned area and fire radiative energy methods. Our integrated method combines the strengths of both the burned area and fire radiative energy methods, enhancing the accuracy of FCE estimation. The results show that the method improves the overall FCE estimate by 70.2 % compared to that of the burned area method alone. Based on the high-resolution inventory and the spatiotemporal cube technique, we identified the spatiotemporal heterogeneity of FCE and high-resolution multi-modal hotspot distributions. These include the El Niño-driven intra-annual 'double peaks' observed in Southeast Asia (SEA) in 2015 and 2019 and the seasonal variability of emissions between Mainland and Equatorial SEA. Forest fires, concentrated in Myanmar and Laos, are the largest source of FCE in SEA. Meanwhile, sporadic hotspots dominate in SEA, reflecting intermittent meteorological and anthropogenic influences. Moreover, by combining this inventory with a database of carbon dioxide from fossil fuel consumption, we reveal the structural dynamics of carbon dioxide emissions, highlighting the critical role of FCE in achieving regional carbon neutrality. This study offers significant insights into the spatiotemporal dynamics of FCE and provides actionable pathways for mitigation strategies and sustainable wildfire management.