The scientist gave tips on observing silvery clouds in June and July

The silvery clouds that appear in the summer months are best observed outside the city, away from artificial lighting. Oleg Ugolnikov, a senior researcher at the Space Research Institute of the Russian Academy of Sciences, Candidate of Physico-Mathematical Sciences, told about this on June 29.

"Temperatures are not so low to the south, and "white nights" are coming to the north, and the sky is too bright for observations of silvery clouds. You can watch them everywhere, but it's better outside the city: less glare, a more open horizon. It is difficult to predict the appearance of silvery clouds. There is a five—day frequency due to planetary waves, but this is not always the case," Ugolnikov said in an interview with RIA Novosti.

The most favorable conditions for observations are in the middle zone of Russia, at latitudes from 50 to 60 degrees, in June and July. During this period, the temperature in the upper mesosphere at an altitude of 80-85 km can drop below 145 degrees Kelvin. Under such conditions, ice crystals are formed, which are illuminated by the Sun and create a silvery glow effect.

According to the scientist, the frequency of appearance of silvery clouds has been increasing in recent years. This may be due to the gradual cooling of the summer mesosphere due to the greenhouse effect - in the upper atmosphere, on the contrary, it lowers the temperature, delaying the thermal radiation of the Earth. Growth is also affected by an increase in water vapor content at various heights.

"This may be due to the gradual cooling of the summer mesosphere due to the greenhouse effect - in the upper layers it lowers the temperature, trapping the thermal radiation of the Earth above the surface, as well as an increase in the content of water vapor at different altitudes in the atmosphere," the expert explained.

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