CHONGQING (CQNEWS) -- On the morning of September 7, there were beautiful stratospheric clouds appearing over the Dazu urban area. It was White Dew of the 24 solar terms. Stratospheric clouds are formed when an air mass passes by relatively cool underlying surface, related to the relatively large day temperature variation when the autumn comes. Contributing photographer Luo Guojia (Translated by Huang Juan, Fathom Language Limited)