The Held-Hou Model is a model for the Hadley circulation of the atmosphere that would exist in the absence of atmospheric turbulence. The model was developed by Isaac Held

Isaac Held

Isaac Held is an American meteorologist. He is currently head of the Weatherand Atmospheric Dynamics Group at the Geophysical Fluid Dynamics Laboratory.Held was elected to the United States National Academy of Sciences in 2003.-Biography:...

 and Arthur Hou in 1980. By comparing a motionless atmosphere

Atmosphere

An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 where the air is radiatively cooled with one where motion is allowed, a number of aspects of the atmosphere's overturning circulation are modelled. In particular, the circulation terminates before reaching the poles. The Hadley circulation has a cooling effect at and near the equator

Equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

 and a warming effect at higher latitudes within the Hadley Cell. The latitudinal extent of the Hadley Cell can be calculated and the effects of moisture

Moisture

Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...

 and seasons can be incorporated into the model.