<P> The trade winds are the prevailing pattern of easterly surface winds found in the tropics , within the lower portion of the Earth 's atmosphere , in the lower section of the troposphere near the Earth 's equator . The trade winds blow predominantly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere , strengthening during the winter and when the Arctic oscillation is in its warm phase . Trade winds have been used by captains of sailing ships to cross the world 's oceans for centuries , and enabled European empire expansion into the Americas and trade routes to become established across the Atlantic and Pacific oceans . </P>
what purpose did seasonal monsoon winds have on trade
enabled European empire expansion into the Americas and trade routes to become established across the Atlantic and Pacific oceans