Transcript dfafafad
Air Movement Chapter 4 – Section 3 Pages 103 - 107 Wind The movement of air from an area of high pressure (more dense) to an area of low pressure (less dense) Global Winds Wind current on a global scale. • Warm air rises and cold air sinks. • Rising and sinking air makes pressure differences Temperature Differences Pressure Difference Global Temperature Patterns The sun’s rays are weaker near the poles causing less warming. The air here is cool. Cool air sinks. The sun’s rays are stronger near the equator causing more warming. The air here is warm. Warm air rises Global Winds Hadley Cells. • Air moves between the equator and the poles. Global Winds The Coriolis Effect • The Earth’s rotation causes air to turn to the right in the Northern Hemisphere and to the left in the Southern Hemisphere Coriolis Effect Mr. Fetch’s Earth Science Classroom Global Winds Remember, winds are named from where they come. Polar Easterlies - From 90°N to 60°N - Deflected to right Prevailing Westerlies - From 30°N to 60°N - Deflected to right 60° N Easterly Trade Winds - From 30°N to O° - Deflected to right Doldrums 30° N 0° Easterly Trade Winds - From 30°S to 0° - Deflected to left Prevailing Westerlies - From 30°S to 60°S - Deflected to left Polar Easterlies - From 90°S to 60°S - Deflected to left 30° S 60° S Doldrums Low Pressure Zone (warm, less dense air) along the equator Heated air expands creating a zone of low pressure Very little wind Rains nearly every afternoon Polar Easterlies 90˚ - 60˚ latitude Winds move east to west Winds rise at 60˚ latitude and sink at the poles Bring us the cold polar air Prevailing Westerlies 60˚ - 30˚ latitude Winds move west to east Winds rise at 60˚ and sink at 30˚ Move weather systems across the United States Easterly Trade Winds 0˚ - 30˚ latitude Winds move east to west Winds rise at the equator and sink at 30˚ Early sailors used winds to navigate trade routes Jetstreams Narrow belts of strong winds near the top of the troposphere Winds move west to east - faster in winter Form between cold dry air and warm moist air Produce large weather systems Jets fly faster when flying with Jet Stream Jet Stream Sea Breeze Convection current of air created during the day from the sea to land Land warms faster than the sea. Warm, less dense air over land rises; cooler, more dense air over sea sinks, creating a cool breeze to blow in from the sea Sea Breeze Land Breeze Convection current of air created at night from the land to sea Land cools faster than the sea. Cooler, more dense air over sinks and moves towards the sea; warmer air over the sea rises, creating a breeze from land to sea Land Breeze