Hadley Cell A direct, thermally driven overturning cell in the atmosphere consisting of
poleward flow in the upper troposphere, subsiding air into the subtropical anticyclones, return flow as part of the trade winds near the surface, and with rising air near the equator in the so - called Intertropical Convergence Zone.
As discussed by Henry Stommel, these flows are balanced in the region of the western boundary, where a thin
fast polewards flow called a western boundary current develops.