East Africa (EA) suffers from the inadequate characterization of atmospheric aerosols, with far-reaching consequences of its inability to quantify precisely the impacts of these particles on regional climate. The current study aimed at character-izing absorption and radiative properties of aerosols using the long-term (2001-2018) AErosol RObotic NETwork (AERONET) and Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data over three environ-mentally specific sites in EA. The annual mean absorption aerosol optical depth (AAOD440 nm), absorption Angstrom Ex-ponent (AAE440-870 nm), total effective radius (REff), and total volume concentration (mu m3/mu m2) revealed significant spatial heterogeneity over the domain. The study domain exhibited a significant contribution of fine-mode aerosols com-pared to the coarse-mode particles. The monthly variation in SSA440 nm over EA explains the strength in absorption aero-sols that range from moderate to strong absorbing aerosols. The aerosols exhibited significant variability over the study domain, with the dominance of absorbing fine-mode aerosols over Mbita accounting for similar to 40 to similar to 50 %, while weakly absorbing coarse-mode particles accounted for similar to 8.2 % over Malindi. The study conclusively determined that Mbita was dominated by AAOD mainly from biomass burning in most of the months, whereas Malindi was coated with black carbon. The direct aerosol radiative forcing (DARF) retrieved from both the AERONET and MERRA-2 models showed strong cooling at the top of the atmosphere (TOA; -6 to -27 Wm-2) and the bottom of the atmosphere (BOA, -7 to -66 Wm-2). However, significant warming was noticed within the atmosphere (ATM; +14 to +76 Wm-2), an indica-tion of the role of aerosols in regional climate change. The study contributed to understanding aerosol absorption and ra-diative characteristics over EA and can form the basis of other related studies over the domain and beyond.

来源平台：SCIENCE OF THE TOTAL ENVIRONMENT