Air MovementChapter 4 – Section 3

Pages 103 - 107

WindThe 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.

Global Temperature Patterns

The sun’s rays are stronger near the equator causing more warming. The air here is warm.

Warm air rises

The sun’s rays are weaker near the poles causing less warming. The air here is cool.

Cool air sinks.

Global Winds

Hadley Cells.

Mr. Fetch’s Earth Science Classroom

The Coriolis Effect

Global Winds

60°S

30°S

0°

30°N

60°N

Prevailing Westerlies- From 30°N to 60°N- Deflected to rightEasterly Trade Winds- From 30°N to O°- Deflected to right

Polar Easterlies- From 90°N to 60°N- Deflected to right

Polar Easterlies- From 90°N to 60°N- Deflected to right

Easterly Trade Winds- From 30°S to 0°- Deflected to leftPrevailing

Westerlies- From 30°S to 60°S- Deflected to leftPolar Easterlies

- From 90°S to 60°S- Deflected to left

Doldrums

Remember, winds are named from where they come.

DoldrumsLow Pressure Zone (warm, less dense air)

along the equatorHeated air expands creating a zone of low pressure

Very little windRains 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

JetstreamsNarrow belts of strong winds near the

top of the troposphereWinds move west to east - faster in

winterForm between cold dry air and warm

moist airProduce large weather systemsJets fly faster when flying with Jet

Stream

Jet Stream

Sea BreezeConvection 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 BreezeConvection 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