Global Winds, Jet Stream, Gulf Stream, and El Nino Global Patterns Global Winds, Jet Stream, Gulf Stream, and El Nino

Global Winds What are global wind patterns? The equator receives the Sun’s direct rays. Here, air is heated and rises, leaving low pressure areas behind. Moving to about 30 degrees north and south of the equator, the warm air from the equator begins to cool and sink. Between 30 degrees latitude and the equator, most of the cooling air sinking air moves back to the equator. The rest of the air flows toward the poles.

Global Winds

Global Winds What are the trade winds? The trade winds are air movements toward the equator. They are warm, steady breezes that blow almost continuously. The Coriolis effect make the trade winds appear to be curving towards the west. What are the doldrums? The doldrums are an area of calm weather and are formed as winds coming from the south and the north meet near the equator.

Global Winds What are the Prevailing Westerlies? Between thirty and sixty degrees latitude, the winds that move toward the poles appear to curve to the east. Because winds are named from the directions in which they originate, these winds are called prevailing westerlies. Prevailing westerlies in the Northern Hemisphere are responsible for many of the weather movements across the Untied States and Canada. (Think: WWWEEE!! = we have winds that move West to East) What are the Polar Easterlies? At about sixty degrees latitude in both hemispheres, the prevailing westerlies join with the prevailing easterlies to reduce the upward motion. The Polar Easterlies form when the atmosphere over the poles cools. This cool air then sinks and spreads over the surface. As the air flows away from the poles it is turned west due to the Coriolis Effect. Again, because these winds begin in the east, they are called easterlies.

Jet Stream The Jet Stream is a strong high-level wind found in the atmosphere that can reach speeds in excess of 200 mph, usually occurring 6-9 miles above the ground. These winds often steer the movement of surface air masses and weather systems. The 2 jet streams that directly affect the weather in the continental U.S. are the Polar Jet and the Tropical Jet.

Ocean Currents The Gulf Stream is a warm swift current in the Atlantic Ocean that flows from the Gulf of Mexico along the eastern coast of the United States, then northeast towards Europe.