Enhancing accuracy in identifying absorbing aerosol types and their radiative impacts

Aerosol radiative forcing is highly uncertain due to an imprecise quantification of absorbing aerosol type which is most critical. Lack of accurate measurements and characterization of aerosol absorption results in this aerosol parameter being poorly constrained and highly underestimated in climate models. In the methods used earlier to classify aerosol absorption a large fraction remained unidentified. A new classification method, that overcomes these limitations, is developed by leveraging the spectral characteristics of aerosol optical depth (AOD) and single scattering albedo (SSA) of different absorbing aerosols, which remarkably reduces the contribution of unidentified aerosol type to almost nil globally, demonstrating the robustness and enhanced accuracy of this new method. On a global scale, black carbon (BC) and the associated absorbing types dominate contributing >70% annually, Dust and Mixed-Dust contributing the rest. The absorbing aerosol types exhibit quite distinct spatial and seasonal variations. This improved and innovative classification of absorbing aerosol types offers significant potential for advancing research in climate modeling, satellite retrieval, and aerosol-monitoring applications, and will be key to reduce the uncertainty in radiative and climate impact of aerosols.