Convergence Zone

A convergence zone is a region where horizontal air or water flows meet, forcing mass to accumulate and, in the atmosphere, rise. Low-level wind convergence drives upward motion, cloud, and precipitation, which is why the Intertropical Convergence Zone and the South Pacific Convergence Zone are the rainiest belts on Earth. The continuity equation links horizontal convergence to vertical velocity, so convergent surface flow under a divergent upper-level pattern sustains deep convection. At fronts and sea-breeze boundaries, convergence concentrates moisture and triggers thunderstorms. In the ocean, surface convergence drives downwelling and accumulates floating material along the line.