Model analysis of the formation of the semi-direct radiative effect of Siberian biomass burning aerosol in the Arctic
I.B. Konovalov, N.A. Golovushkin
Federal Research Center A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
Keywords: aerosol, smoke, chemistry-transport model, aerosol-radiation interaction
Abstract
Based on simulations performed with the CHIMERE chemistry transport model and WRF meteorological model, we analyzed the processes responsible for the formation of the semi-direct radiative effect (SDRE) of smoke from Siberian fires over snow-ice surfaces in the Arctic. Within the framework of the analysis, time and space averaged changes in the radiative fluxes, cloud parameters in different cloud layers, and some meteorological characteristics associated with cloud formation processes due to the radiative impact of Siberian biomass burning aerosol (SBBA) have been considered. The results show that the scattering of the solar radiation by SBBA particles increases the static stability of the atmosphere at altitudes of 2-4 km and suppresses vertical turbulent motions, which decreases the rate of water condensation, the optical thickness of clouds, and the ratio of the mixture of condensed water in the mid-level and partially low-level clouds. The decrease in the optical thickness of the clouds, in turn, causes the appearance of a positive SDRE of SBBA at the top and bottom of the atmosphere. Absorption of radiation by SBBA particles does not play a fundamental role in these processes, although it causes addition changes in the meteorological characteristics.
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