Thickness of the dry convection and large-scale subsidence above deserts

Thickness of dry convection above various deserts of the world is obtained from aerological data, and assimilated data from ECMWF. A mixed layer develops up to a height of about 1 km above the central Sahara, where strong subsidence occurs. However, above many other deserts in Africa and Asia, a deep mixed layer develops up to 4-6 km. These mixed layers develop to a high altitude because the daytime mixed layer links with an existing weakly stratified, near-neutral layer above. Large-scale subsidence does not reach the surface throughout the day, except in the winter season. Mixed-layer height is shallower in the Southern Hemisphere than in the Northern Hemisphere in the summer season.