Measurements of aerosol particle concentrations in the atmosphere of the south-eastern coast of Lake Baikal (at Boyarsky station) in the summer of 2020

Abstract

Atmospheric measurements of aerosol particle concentrations were made at a station named Boyarsky, the south-eastern coast of Lake Baikal (Russia) in the summer of 2020. The measurement period was conventionally divided into two ranges: 1) the smoke emission period of July 17-25; 2) the period of weakening of the influence of smoke emissions from forest fires in the neighbouring regions (from 14 August to 10 September). The diurnal behaviour of the total number concentrations of ultrafine particles in the size range from 5 to 200 nm (UFA) and submicron aerosols (SMA) from 0.2 to 1 μm was studied. The mean concentrations of UFA and SMA are 2705 (±1791) cm−3 and 40 (±19) cm−3 in July; 1247 (±780) cm−3 and 57 (±58) cm−3 in August; 1205 (±764) cm−3 and 37 (±19) cm−3 in September, respectively (the values in parentheses represent the respective standard deviations). The temporal evolution of the UFA particle number concentrations has shown a pronounced variation with lower concentrations in August-September and higher concentrations in July, whereas the diurnal patterns have been mostly found to be strongly influenced by the wildfire emissions. A strong relationship between the total particle number concentration has been established with the concentration of nitrogen dioxide NO2 (R =0.81), O3 (R = 0.66) and a weaker one with the concentration of sulphur dioxide (R =0.46). The thus obtained data on aerosol particle concentrations have been used to identify the events of bursts of nanoparticle formation in the atmosphere.