Intertropical Convergence Zone it is sometimes referred to as a monsoon trough, a usage more common in Australia and parts of Asia. In the seamen's speech, the zone is referred to as the doldrums because of its erratic (monotonous) weather patterns with stagnant calms and violent thunderstorms. The ITCZ appears as a band of clouds, usually thunderstorms, that encircle the globe near the Equator. In the Northern Hemisphere, the trade winds move in a southwestward direction from the northeast, while in the Southern Hemisphere, they move northwestward from the southeast. When the ITCZ is positioned north or south of the Equator, these directions
South Pacific convergence zone its orientation and location. It is often distinct from the ITCZ over Australia, but at times they become one continuous zone of convergence. The location of the SPCZ is affected by ENSO and Interdecadal Pacific oscillation conditions. It generally stretches from the Solomon Islands through Vanuatu, Fiji, Samoa, and Tonga. Low-level convergence along this band forms cloudiness as well as showers and thunderstorms. Thunderstorm activity, or convection, within the band is dependent upon the season, as the more equatorward portion is most active in the Southern Hemisphere summer, and the more poleward portion is most active during transition seasons of