June 17, 2013. Night glowing noctilucent clouds are another unusual and little-studied type of clouds. They were first seen in 1885 after the eruption of Krakatoa. It is therefore considered that they are formed by the condensation of water vapor on the dust particles, followed by its transformation into ice. All this occurs at high altitudes (noctilucent clouds are the highest clouds).
Recently these clouds appear increasingly, including in the lower latitudes.
A number of scientists is of the opinion that the increase in emissions of methane, which comes in a complex reaction with water vapor, catalyzes the formation of noctilucent clouds. Other researchers assign a major role in the formation of these clouds lowering of the temperature of the lower stratosphere due to global warming is happening, which ultimately is the cause of the various changes in the atmospheric circulation.