[MIS01-P09] Distribution of trace gases and aerosols in the Siberian air shed during wildfires of summer 2012
Keywords:Atmosphere, Aerosol, Greenhouse gases, Wildfires
Highest concentrations of CO2, CH4 and CO over wildfire spots reached 432 ppm, 2367 ppb, and 4036 ppb, correspondingly. If we exclude from the analysis the data obtained when crossing smoke plumes, we can find a difference between background concentrations measured in the atmosphere over regions affected by biomass burning and clean areas. Enhancement of CO2 over the wildfire areas changed with altitude. On average, it was 10.5 ppm in the atmospheric boundary layer (ABL) and 5-6 ppm in the free troposphere. Maximum CO2 enhancements reached 27 ppm and 24 ppm, correspondingly. The averaged CH4 enhancement varied from 75 ppb in the boundary layer to 30 ppb in the upper troposphere, and a little bit lower than 30 ppb in the middle troposphere. Maximum CH4 enhancements reached 202 ppb, 108 ppb, and 50-60 ppb, correspondingly. The averaged and maximum enhancements of CO differed by an order of magnitude. Thus, in the ABL the maximum difference in concentration between clean and wildfire areas reached 2300 ppb, while averaged one was 170 ppb. In the middle troposphere maximum enhancements varied from 1000 to 1700 ppb.
The vertical distribution of ozone has its own peculiarities. Ozone concentration decreased in the layers with enhanced aerosol concentration and it increased in the areas with lower aerosol content. At the same time, photochemical production ozone was observed at the plume edges in the zone of fresh air entrainment.
This work was supported by the Russian Foundation for Basic Research (grant No 17-05-00374).