Global Winds

Wind Caused by differences in air pressure Air moves from areas of high pressure to areas of low pressure Types of winds: Trade winds Wind Direction Westerlies Direction from which the wind is coming, NOT the direction it is blowing Polar easterlies Jet stream Sea breeze Ex. North winds blow from N to S Land breeze

Global Wind Patterns Blow steadily across Earth in paths that are thousands of kilometers long Steer weather in certain directions (usually west to east in the U.S.) Caused by thermal energy from the sun The sun does not heat the surface evenly causing uneven heating of the atmosphere.

Global Winds

Global Wind Belts Coriolis Effect: Earth’s rotation causes winds to curve to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Creates the prevailing winds Prevailing Winds Trade winds: blow from east to west near the equator. Westerlies: blow from west to east in the mid-latitudes. Polar Easterlies: cold winds that blow from the east to the west near the North and South Poles

Global Wind Belts Jet Streams: narrow band of high winds near top of the troposphere flow around Earth from west to east, often making large loops to the north or the south Influence weather as they move cold air from the poles toward the tropics and warm air from the tropics toward the poles Can move up to 300 km/h

Local Winds Occur whenever air pressure is different from one location to another Sea Breezes wind that blows from the sea to the land due to local temperature and pressure differences Land Breezes Wind that blows from the land to the sea due to local temperature and pressure differences