Air

High altitude winds

In theory, one might expect ground level winds to be coupled with similar winds, blowing in the opposite direction, at high altitudes, in the higher strata of the troposphere. In practise, however, from observations that have been carried out, it has been shown that above an altitude of 4-5.000 m there are only westerly currents that move from West to East roughly following the route of the parallels. Only above the Equator there is a narrow band of easterly winds that are probably connected to the convergence zone of the trade winds. The speed of high altitude winds is proportional to height. The greatest speed is reached at the limit of the troposphere. These winds are slower at the Equator, they grow in speed at the middle latitudes and slow down again closer to the Poles. It is not quite clear as yet which is the mechanism that brings about this type of circulation at high altitudes, but, whichever the origin, the role of high altitude winds is fundamental in the distribution of cyclonic and anticyclonic areas in the world.