Exploring large-scale black-carbon air pollution over Northern Eurasia in summer 2016 using MERRA-2 reanalysis data

The abnormally high temperature and the deficit of precipitation in Siberia in summer 2016 contributed to the development of massive forest fires, which resulted in pyrogenic emission in the atmosphere of various biomass burning products. This paper presents the analysis results of the spatial and temporal variations of black carbon (BC) in the atmosphere over Northern Eurasia during the 2016 Siberian wildfires using the MERRA-2 reanalysis data. The spatiotemporal evolution of BC anomalies is presented, with estimates of the increase in BC mass during wildfire period. The peculiarities of large-scale atmospheric circulation responsible for BC transport from Siberia to Central Europe are discussed. The estimates of spatial scale, effective height and speed of the long-range anomalous (from east to west) transfer of air masses in the atmosphere over Northern Eurasia in July 2016 are obtained. Changes in the optical and microphysical characteristics of biomass-burning aerosol during its long-range transport are also discussed. A comparison of daily variations in surface BC concentrations at the polar observatory Tiksi with those in BC column mass density from MERRA-2 revealed a high correlation between local and integral characteristics of BC during arriving air masses from Siberian wildfires.