The Watchers-4/14/13, Chiffre
Take a look at a physical map of the world. Thirty degrees on either side of the equator, you will see, distributed with suspicious regularity, a brown band of drylands circling the planet, a sere belt warding off greener climes: the deserts of the world. They are positioned in the so-called Horse Latitudes, where constant high-pressure systems drive away the rain clouds, and swirl above the earth because of global temperature variations and the Coriolis Effect produced by the earth’s rotation in space. These areas within the Horse Latitudes are under the influence of two bands of high atmospheric pressure called the subtropical high pressure belt or subtropical ridge which is formed by the sinking air of the Hadley cell.
The heating of the tropics produces a huge amount of rising warm, moist air that creates the Intertropical Convergence Zone, a band of thick cloud. This warm, moist air moves towards the poles at high altitudes and then cools and sinks in the mid-latitudes in both hemispheres, creating the Hadley Cell. The Hadley Cell is possibly the most fundamental factor in the global climate system, redistributing the heat and moisture from the tropics to the higher latitudes. Many of the world’s deserts are caused by these climatological phenomena.
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