the planet's oldest cargo route, running on sunlight instead of diesel.
means steady easterly winds blowing from the subtropics toward the equator, driven by hot air rising and cooler air rushing in to replace it.
from from old english trade meaning path or track, later merged with the nautical sense once sailors realized these winds held a reliable direction you could set a course by, literally winds you could trade on.
manila galleon route — spanish ships rode them across the pacific for 250 years, 1565 to 1815
columbus 1492 crossing — used northeast tradewinds to reach the caribbean in 5 weeks
triangular trade — powered the atlantic slave and sugar trade routes for three centuries
hokulea voyage — 1976 polynesian canoe used them to sail hawaii to tahiti without instruments