Biomass burning aerosol impact on surface winds during the 2010 Russian heat wave

Abstract

This paper elucidates the impact of biomass burning aerosols (BB) on surface winds for the Russian fires episode during 25 July to 15 August 2010. The methodology consists of three Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulations over Europe differing in the inclusion (or not) of aerosol-radiation and aerosol-cloud interactions. The presence of BB reduces the 10 m wind speed over Russia during this fire event by 0.2 m s−1 (10%). Aerosol interactions imply a decrease of the shortwave downwelling radiation at the surface leading to a reduction of the 2 m temperature. This decrease reduces the turbulence flux, developing a more stable planetary boundary layer. Moreover, cooling favors an increase of the surface pressure over Russian area and also it extends nearby northern Europe.