STS040-75-003 (5-14 June 1991) --- This image shows several of the Canary Islands, located in the North Atlantic Ocean just west of Africa.  Low level stratus clouds often form here (and along the west coast of continents at these latitudes) are trapped in vertical movement due to an overlying atmospheric temperature inversion.  The islands are generating disturbances in the low-level wind flow which is generally from the north-northeast or from top to bottom in the image.  These disturbances travel downstream from the islands and manifest themselves as cloud swirls which are called von Karman vortices.  The northern extent of a large dust storm moving off the coast of Africa is apparent at the lower right of the image.  The dust, extended across the Atlantic Ocean as far west as the Dominican Republic later in the mission.
Canary Island Group and von Karman Cloud Vortices.
Stable, south flowing air over the western Pacific Ocean (26.0N, 131.0E) is disturbed by islands south of Korea, resulting in sinuous clouds known as von Karman vortices. The smoke plume from Japan's Mount Unzen Volcano on Kyushu, is visible just west of the large cloud mass and extending southward. A very large, purple tinged dust pall, originating in Mongolia, can be seen on the Earth's Limb, covering eastern China and extending into the East China Sea.
Volcanic Plume from Mt. Unzen, Dust Cloud, cloud Vortices