Interannual and Seasonal Variation of Optical and Microphysical Properties of Aerosol in the Baikal Region

Abstract

The paper analyzes the interannual, seasonal variations of the optical and microphysical characteristics of aerosol in the Baikal region atmosphere according to measurements using the CIMEL sun photometer of the AERONET network at Tory station and according to the data of expedition measurements using the SP-9 sun photometer on the southeastern coast of Lake Baikal from 2010 to 2020. It is shown that in recent years, there has been an increase of the average monthly aerosol optical depth (AOD) values in the summer months, which is consistent with an increase in smoke emission due to annual large-scale wildfires in the boreal forests of Siberia and Yakutia in summer. Aerosol classification was carried out based on filtration and selection of the prevailing types of aerosols by analysis of aerosol optical depth and Angstrom exponent. It was revealed that in summer, the proportion of the smoke component of the aerosol optical depth increases to 30% compared to the spring. In the presence of smoke advection, the close relationship of AOD with the concentrations of the microdispersed aerosol fraction PM10 and PM2.5 was revealed. The correlation coefficients between the concentration of particulate matter (PM10 and PM2.5) and AOD were 0.87 and 0.86, respectively.

Variability of aerosol concentrations of fractions PM10 and PM2.5 in the atmosphere surface layer at the reference monitoring station Boyarsky

“…Increased concentrations of fine dispersed aerosols in the warm period are due to additional emission of organic aerosol during the flowering period of plants, soil aerosol, the influence of smoke aerosol from wildfires and peat fires, etc. [11].…”

Results of AOD measurements and aerosol dispersion composition in atmosphere of the Baikal region during wildfires in summer 2021

“…Figure 1c shows a decrease in the singlescattering albedo with wavelength, which is typical for the predominance of absorbing aerosols in the atmosphere, such as black carbon. In the long-term change in the finely dispersed component of AOD, a growth trend and high variations due to smoke from wildfires were noted [7]. To identify the main features of the spatiotemporal variability of aerosol characteristics in the atmosphere of the Baikal region, the average spectral characteristics of the aerosol optical depth of the atmosphere for the "smoke/clear atmosphere" conditions are considered.…”

Variation of Aerosol Optical Properties over Cluj-Napoca, Romania, Based on 10 Years of AERONET Data and MODIS MAIAC AOD Product

“…Natural, largescale events of aerosol intrusions have been researched by Sun et al (2022), who studied two extreme dust events over North China in March, 2021, by using AERONET in situ observations and CALIPSO satellite data to obtain the distribution characteristics of dust aerosol optical properties along their transport pathways [11]. Additionally, Dementeva et al (2022) analyzed AERONET data collected over a 10-year period, and found that there was a significant increase in smoke aerosols during the summer months, which was caused by large-scale wildfires in the boreal forests surrounding Lake Baikal [12]. In Southeastern Europe, long-term aerosol trends have been researched using AERONET datasets.…”