Trade winds both hemispheres by the Coriolis effect. These winds blow predominantly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere. Because winds are named for the direction from which the wind is blowing, these winds are called the northeasterly trade winds in the Northern Hemisphere and the southeasterly trade winds in the Southern Hemisphere. The trade winds of both hemispheres meet at the doldrums. As they blow across tropical regions, air masses heat up over lower latitudes due to more direct sunlight. Those that develop over land (continental) are drier and hotter than those that
Trade winds within the subtropical ridge. The weaker the trade winds become, the more rainfall can be expected in the neighboring landmasses. The term "trade winds" originally derives from the early fourteenth century late Middle English word "trade," meaning "path" or "track." The Portuguese recognized the importance of the trade winds (then the "Volta do mar", meaning in Portuguese "turn of the sea" but also "return from the sea") in navigation in both the north and south Atlantic ocean as early as the 15th century. From West Africa, the Portuguese had to sail away from continental Africa, that is, to west and