The work addresses the issue of how much cloud cover data obtained using model-interpolation techniques are suitable for monitoring the transparency of the atmosphere and determining conditions for the Earth's airglow observations at a local geophysical observatory. For this purpose, we compared the temporal dynamics of cloud cover from ECMWF's ERA5 with the night atmosphere transparency according to a digital camera. We considered the dynamics of the addressed parameters over December 2020 at the Geophysical Observatory of the Institute of Solar-Terrestrial Physics, located in the Baikal Natural Territory near the village Tory (Republic of Buryatia, Russia). The comparative analysis showed a generally good agreement between cloud cover data from ECMWF's ERA5 climate reanalysis and those observed with the camera. Disadvantages are the lack of information on rapid variations in cloud cover in the reanalysis and positive and negative delays in the dynamics of cloud fields that last about two hours.

The study was financially supported by the Ministry of Science and Higher Education of the Russian Federation (Subsidy no.075-GZ/C3569/278) and the grant No. 075-15-2020-787 for implementation of Major scientific projects on priority areas of scientific and technological development (the project «Fundamentals, methods and technologies for digital monitoring and forecasting of the environmental situation on the Baikal natural territory»).