Surface Ocean Currents

Atmospheric circulation and the Coriolis effect create global wind patterns including the trade winds and westerlies.

In the Northern Hemisphere, warm air around the equator rises and flows north toward the pole. As the air moves away from the equator, the Coriolis effect deflects it toward the right. It cools and descends near 30 degrees North latitude. The descending air blows from the northeast to the southwest, back toward the equator (Ross, 1995). A similar wind pattern occurs in the Southern Hemisphere; these winds blow from the southeast toward the northwest and descend near 30 degrees South latitude.

These prevailing winds, known as the trade winds, meet at the Intertropical Convergence Zone (also called the doldrums) between 5 degrees North and 5 degrees South latitude, where the winds are calm. The remaining air (air that does not descend at 30 degrees North or South latitude) continues toward the poles and is known as the westerly winds, or westerlies. The trade winds are so named because ships have historically taken advantage of them to aid their journies between Europe and the Americas (Bowditch, 1995).

Where this page came from

This page was imported from NOAA National Ocean Service. A lesson from NOAA's National Ocean Service tutorials; as a work of the United States government, in the public domain.

Nobody has written it yet — it is the source material at a new address, which is why search engines are asked to skip it and why no one earns from it. It is up for grabs: take it on, and it is yours to rewrite and to earn from.