zonal flow

Zonal flow refers to atmospheric circulation patterns that generally move in an east-west direction, encircling the Earth in belts. These patterns are influenced by large-scale pressure systems, such as high-pressure belts near latitudes 30° N and S (horse latitudes) and low-pressure areas near the Equator.12

In tropical and subtropical regions, trade winds blow westward and equatorward from high-pressure centers. Near the Equator, these winds converge in the Intertropical Convergence Zone (ITCZ), leading to showers and thunderstorms.12

In the middle latitudes, prevailing winds are known as westerlies, which blow eastward. These are associated with changeable weather, including storms and periods of dry conditions. Jet streams, which are narrow bands of very strong winds, are often found within the westerly flow at higher altitudes. The Southern Hemisphere generally exhibits more uniform zonal winds due to less landmass interference compared to the Northern Hemisphere.134