Atmosphere Contents

5. General Circulation

There are distinct characteristics of the general circulation at low-latitudes

Heating of the Earth is greatest over the equator. Air rises in this region, often condensing into huge cumulus clouds and thunderstorms, liberating an enormous amount of latent heat which makes the air more buoyant. As the air rises it reaches the tropopause (the top of the troposphere, the lower part of the atmosphere) which acts as a barrier. Consequently the air has to move laterally towards the poles. However, the trajectory of an air parcel moving under the influence of a pressure gradient is less constant than one might think, due to the Coriolis force. This force, associated with Earth's rotation, deflects all objects not at the equator, to the right of the direction of motion in the northern hemisphere and to the left in the southern hemisphere. This provides westerly winds, aloft in both hemispheres, that can produce jet streams.

General circulation

What are the distinct characteristics of the general circulation of low-latitudes?