Space traffic may be cause of increase in polar mesospheric clouds



A recent increase in polar mesospheric clouds could be due to a recent increase in space traffic, a new study suggests. Polar mesospheric clouds are diffuse collections of water ice crystals in the mesosphere near the poles at altitudes of about 80 kilometers. The number and brightness of polar mesospheric ice clouds is expected to decrease when the incoming flux of solar ultraviolet radiation increases. Increases in solar radiation heat and dry out the atmosphere slightly, leading to a decrease in ice cloud formation.