Pacific Trade Winds

The steady easterly winds of the tropical Pacific, blowing from the subtropical highs toward the equator (northeast in the northern hemisphere, southeast in the southern), that governed sailing-ship routing. The Manila Galleon used them for the westbound Acapulco-to-Manila run from 1565, then rode the higher-latitude westerlies and the Kuroshio for the eastbound return that Andres de Urdaneta charted. The doldrums and the El Nino-Southern Oscillation interrupt the pattern; trade-wind reliability defined the galleon’s sailing windows.