Aerosol Optical Depth of the Atmosphere near TAIGA Gamma-ray Observatory According to GEOS-CHEM Chemical Model and CAMS Chemical Reanalysis

Atmospheric aerosol affects astronomical observations in the visible spectral region (400−700 nm). Therefore, information on the dynamics of optical properties of the atmosphere in the region of an astrophysical experiment is required for correct interpretation of experimental results. In the lack of local measurements, data on the state of the atmosphere can be derived, for example, from numerical simulation. The paper discusses the simulation results for AOD in the region of TAIGA gamma-ray observatory, where EAS Cherenkov radiation is recorded at night, with the use of GEOS-CHEM chemical transport model and CAMS chemical reanalysis. According to GEOS-CHEM and CAMS data, the average AODs (at a wavelength of 550 nm) over September–April in 2019–2022 were ∼0.08 and ∼0.05, respectively. The AOD maximum is observed in April and can attain 0.6. Verification of the simulation results with AERONET data shows their satisfactory agreement: the correlation coefficient is 0.92 for GEOS-CHEM and 0.91 for CAMS. Hence, the results of GEOS-CHEM and CAMS can be used for processing data from TAIGA gamma-ray observatory, as well as from similar astrophysical projects.