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
Trade winds northwest. They could then turn northeast, to the area around the Azores islands, and finally east to mainland Europe. They also learned that to reach South Africa, they needed to go far out in the ocean, head for Brazil, and around 30°S go east again. Following the African coast southbound means upwind in the Southern hemisphere. In the Pacific ocean, the full wind circulation, which included both the trade wind easterlies and higher-latitude Westerlies, was unknown to Europeans until Andres de Urdaneta's voyage in 1565. The captain of a sailing ship seeks a course along which the winds can be