Structure in polar mesospheric clouds seen from a geostationary spacecraft

Polar mesospheric clouds seen from space not infrequently show two layers, sometimes more, or a thickening of the layer if not downright separation into layers. This is often seen in images of polar mesospheric clouds obtained from spacecraft in geostationary orbit. Examples are shown here from the so‐called VIS data of the European geostationary meteorological satellite, Meteosat 5, and it is argued that these structures could well result from a single, thin, layer of cloud which is tilted over some of its extent, perhaps because of the presence of waves in the layer.