Analysis of brown carbon content and evolution in Siberian biomass burning smoke plumes using AERONET data
N.A. Golovushkin1, I.N. Kuznetsova2, I.B. Konovalov1, M.I. Nahaev2, V.S. Kozlov3, M. Beekmann4
1Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS), Nizhny Novgorod, Russia
2Hydrometeorological Centre of Russia, Moscow, Russia
3V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
4Laboratoire Interuniversitaire des SystГЁmes AtmosphГ©riques, France
Keywords: дымовой аэрозоль, коричневый углерод, сибирские пожары, AERONET, biomass burning aerosol, brown carbon, Siberian fires, AERONET
Abstract
The content and evolution of brown carbon (BrC) in biomass burning smokes from Siberian forest fires were analyzed using measurements of the absorption aerosol optical thickness at three AERONET stations situated in Tomsk (in Siberia), Zvenigorod (near Moscow), and Yekaterinburg (at the Ural). The analysis resulted in estimates of the relative contribution of BrC in fine aerosol particles to the absorption of solar radiation at a wavelength of 440 nm (hBrC), in particular, for an anomalous episode of the long-range transport of biomass burning smoke from Siberia into the European part of Russia in summer 2016. A considerable fraction of BrC is found in smoke aerosol over Tomsk and Zvenigorod (where hBrC is estimated to be about 15 and 18% on average), while the estimates of hBrC for Yekaterinburg are found to be insignificant. The analysis also revealed a decrease in hBrC in the process of aerosol aging under the illuminated conditions on the time scale of about 30 h. At the same time, the measurements in Zvenigorod indicate an increase in the absorption properties of the organic fraction of biomass burning aerosol after much longer atmospheric evolution.
|
