The Hadley cell is the atmospheric circulation cell spanning the equator to roughly 30 degrees latitude in each hemisphere.
Strong solar heating near the equator warms moist air, causing it to rise. Near the top of the troposphere, that air moves poleward, cools, and descends in the subtropics. Near the surface, it returns toward the equator as part of the trade-wind circulation.
The rising branch is associated with frequent clouds and heavy rainfall in the Intertropical Convergence Zone. Descending air near 30 degrees is generally dry, helping explain why many major subtropical deserts occur in that latitude belt.
The Hadley cell is not perfectly fixed or symmetrical. It shifts seasonally with the Sun’s apparent position and changes with land, oceans, and climate variability. The Ferrel and polar cells occupy higher-latitude parts of the idealized three-cell model.