Advancing Carbonaceous Aerosol Remote Sensing across Asia-Oceania: Insights from Geostationary Satellite Retrievals

Carbonaceous aerosols, comprising mainly black carbon (BC) and organic carbon (OC), have a substantial impact on radiation balance, the climate, and human health. Despite extensive scientific attention, the challenges associated with current approaches for measuring carbonaceous aerosols, especially low spatial and temporal resolutions, limit the understanding of their sources and dynamics. This study presents a comprehensive analysis of carbonaceous aerosols over the Asia-Oceania region using a novel critical reflectance algorithm for geostationary satellite (Himawari-8/9) retrievals. The findings reveal reasonable spatial and temporal variations in BC and OC, with notable differences between the Northern and Southern Hemispheres. Moreover, we highlight the potential for satellite retrievals to distinguish primary OC sources and secondary OC formation. The impacts of extreme events were evident, such as the COVID-19 lockdown and extreme biomass burning or wildfires, demonstrating the capability of monitoring air quality changes in response to emission variations. The findings of the study contribute to our understanding of short-term climate forcing of carbonaceous aerosols and can support the development of effective policies to reduce air pollution and carbon emissions, thereby achieving carbon neutrality goals.