Optical Turbulence Characteristics at the Special Astrophysical Observatory Site

In this paper, we used meteorological data to simulate vertical profiles of optical turbulence at the Special Astrophysical Observatory (Russia, 43°40′19 ′′ N 41°26′23′′E, 2100 m a.s.l.), site of the 6-m Big Telescope Alt-azimuthal. The vertical profiles of optical turbulence are calculated using ERA-5 reanalysis data. These profiles are corrected using DIMM measurements as well as estimations of atmospheric boundary layer heights. We may note that the method basically reconstructs the most important features of the shape of the measured profile under clear sky. Atmospheric turbulent layers were identified, and the strength of optical turbulence in these layers was estimated. The model hourly values of seeing corresponding to the obtained vertical profiles range from 0.85 to 2.10 arcsec, values of the isoplanatic angle vary in the range from 1 to 3.0 arcsec (at λ = 500 nm). These estimations are close to the measured median of seeing (1.21 arcsec).