ИСТИНА

Aerosols were sampled at MO MSU station in Moscow megacity, in spring when complementary impact of agriculture fires around is increased in accordance to biogenic activity and urban emissions. Spectral light absorption evaluated by Angstrom Absorption Exponent (AAE) used to estimate the periods of biomass burning (BB) contribution to urban fossil fuel (FF) combustion. For Moscow megacity aerosols PCA provides the most important variables between aliphatic C-C-H, aromatic С=С-С and С=С-Н, carbonyl С=О as well as sulfates, ammonium, carbonates, and silicates. The score plot shows the daily differentiation on two episodes of high and weak spectral dependence according AAE . Functional Factors of PC loadings identifies the sources of highest variabilities between traffic (diesel, gasoline), dust, spring biogenic and photochemical activity, long-term transportation of BB and secondary inorganic aerosols.