Global Emissions Inventory from Open Biomass Burning (GEIOBB): Utilizing Fengyun-3D global fire spot monitoring data

Open biomass burning (OBB) significantly impacts regional and global air quality, climate change, and human health. It is susceptible to fire types, including forests, shrublands, grasslands, peatlands, and croplands burning. Global high-resolution satellites have advantages in detecting active fires, enabling more accurate estimation of these emissions. In this study, we develop a global high-resolution (1 km×1 km) daily emission inventory associated with OBB emissions using the Chinese Fengyun-3D satellite’s global fire spot monitoring data, satellite and observational biomass data, vegetation index-derived spatiotemporal variable combustion efficiency, and land type-based emission factors. The results showed that the average annual OBB emissions for 2020–2022 were 2,586.88 Tg C, 8841.45 Tg CO₂, 382.96 Tg CO, 15.83 Tg CH₄, 18.42 Tg NO_X, 4.07 Tg SO₂, 18.68 Tg OC, 3.77 Tg BC, 5.24 Tg NH₃, 15.85 Tg NO₂, 42.46 Tg PM_2.5 and 56.03 Tg PM₁₀. More specifically, taking carbon emissions as an example, the average annual OBB for 2020–2022 were 72.71 (BONA), 165.7 (TENA), 34.1 (CEAM), 42.9 (NHSA), 520.5 (Southern Hemisphere South America; SHSA), 13 (EURO), 8.4 (MIDE), 394.3 (Northern Hemisphere Africa; NHAF), 847 (Southern Hemisphere Africa; SHAF), 167.4 (BOAS), 27.9 (CEAS), 197.3 (Southeast Asia; SEAS), 13.2 (EQAS), and 82.4 (AUST) Tg. SHAF was identified as the regions with the largest emissions. Notably, Savanna Grassland accounted for the lion's share of the total emissions, contributing a substantial 46%, followed by Woody Savanna/Shrubs at 33%. Moreover, a notable seasonal variability characterizes OBB carbon emissions, with a marked escalation observed in July and August. This surge in carbon emissions is chiefly attributed to fires in Savanna Grasslands, Woody Savanna/Shrubs, and Tropical Forests of SHAF, SHSA, and NHAF. Fires in Savanna Grasslands were predominant in NHAF, contributing to 77% of emissions during January–April, while in SEAS, Woody Savanna/Shrubs (52%) and Tropical Forests (23%) were the primary sources. Our comprehensive high–resolution inventory of OBB emissions provide valuable information for enhancing the accuracy of air quality modelling, atmospheric transport and biogeochemical cycle studies.