Hadley cell

Hadley cell is a term used in meteorology, the model describes a circulation pattern within the troposphere between the subtropical high pressure belt and the equator. The Hadley cell, named after its discoverer George Hadley.

The fact that the sun in the equatorial region at the zenith (90 ° angle of incidence ), here the ground-level air masses heat up the most. The heated air less dense (ie expands ) and rises, making the ground a pronounced globe for seamless trough of low pressure is created.

As you ascend, the air cools with increasing altitude. At the tropopause, at about 18 kilometers altitude, it flows because of the comparatively high air pressure to the north and south. The air further cools and loses height. Due to the oncoming air masses increases near the ground, the air pressure, it forms the subtropical high pressure belt. From here, the air follows the pressure gradient and flows into the equatorial trough of low pressure in the region of Zenitalstands the sun back. The coincident there from northern and southern directions from air masses form the intertropical convergence zone (ITC ). It thus forms a large-scale air circulation.

The resulting surface winds are called trade winds.