Surface winds that blow in the direction of the equator are called "trade winds." These winds blow from around 30 degrees north or south latitude toward the equator. In the Northern Hemisphere, trade winds generally blow from the northeast to the southwest, and in the Southern Hemisphere, they blow from the southeast to the northwest. The trade winds are part of the Earth's atmospheric circulation and are caused by air moving from subtropical high- pressure areas toward the equatorial low-pressure zone, deflected westward by the Coriolis effect.