Source categories and contribution of biomass smoke to organic aerosol over the southeastern Tibetan Plateau

► Spring time aerosol characterization in southeastern Tibetan Plateau. ► High levoglucosan and mannosan concentrations at a mountain and suburban site. ► Smoke aerosols from crop residues, softwood and hard wood burning in the study region and Southeast Asia. ► Biomass smoke contributions to OC and OM of up to 38.3 and 45.4%.