Hadley Cell: Warm air rises at the equator, moves toward the poles in the high atmosphere, descends in the subtropics, and returns to the equator near the surface.
Between the Hadley Cell and the Polar Cell, the Ferrel Cell involves cool, polar air descending in the mid-latitudes, migrating toward the equator in the upper atmosphere, and rising in the subtropics.
Cold, dense air sinks at high latitudes, flows near the surface, rises in the polar front, and returns poleward in the upper atmosphere in the Polar Cell.
Trade Winds: Hadley Cell circulation causes sustained easterly winds near the equator. They are vital to maritime navigation.
Westerlies: Mid-latitude westerlies blow from west to east. They affect weather patterns in various locations due to Ferrel Cell circulation.
Arctic easterlies are chilly winds from the east near the poles. They interact with westerlies and circulate with Polar Cells.
The Earth's rotation causes the Coriolis effect, which deflects air to the right in the Northern Hemisphere and left in the Southern. This affects atmospheric circulation.
Westerlies contain high-altitude, fast-flowing jet streams. They are vital to weather system control and surface weather.