Atmospheric Movement and Local Weather

Atmospheric Movement and Local Weather

*Air Masses

*Air Pressure

0 o Equator 30 o S 60 o S 90 o S30 o N60 o N90 o N

MoreDirect Sun Hot

*Convection Currents

*Global Convection Cells

*Global Wind Patterns

*The Coriolis Effect

*The Coriolis Effect Animation

*http://www.youtube.com/watch?v=i2mec3vgeaI

*Jet Stream

*Jet Stream

*Forms high in the upper troposphere between two air masses of different temperatures*Higher temperature difference = faster speed*Due to the Coriolis Effect, it flows around air masses.*Polar Jet:*It dips southward when frigid polar air masses move south.*It tends to stay north in the summer months.

*Jet Stream Animation

*http://www.youtube.com/watch?v=CgMWwx7Cll4

*Reflection Question

*Why does the Earth have wind?

*Variables Affecting Local Weather

*Fronts

*When convection and winds cause air masses to move, they bump into one another.*The area where two air masses meet is called a front.*Most severe weather occurs near frontal boundaries.

*Cold Front- Cold air meets warm air- Fast moving and stormy- Severe weather is likely.

*Cold Front Symbol

*Warm Front- Warm air meets cold air- Slow moving with less severe weather

*Warm Front Symbol

*Stationary Front

*Warm and cool air masses that are not strong enough to move one another

*Sits still for a long period of time

*Stationary Front Symbol

*Friction

*Frontal Boundary

Animation

*High and Low Pressure Circulation

*Air Pressure and Wind

*Air pressure is measured with a barometer in millibars.*Millibars are represented by connected lines of equal pressure. This is a lot like the topographic map lines.*The closer together the lines are, the faster the wind speed.*The farther apart the lines are, the slower the wind speed.

*The Earth’s Insulator

*The Sun heats the water and land every day.*Land heats up rapidly, but cools off rapidly.*Desert

*Water heats up slowly, but cools off slowly.*Swimming at night

*The heat retained by the oceans is what keeps our planet insulated.

*Land and Sea Breezes

*The heating and cooling of water and land produces land breezes and sea breezes.*High pressure moves toward low pressure, pushing the warm air upward.*As warm air rises, cooler air moves in and replaces it.

*Land Breeze

*Sea Breeze

*Sea Breeze and Land Breeze

Animation

*http://www.youtube.com/watch?v=gM0d3fGew-0

*http://www.youtube.com/watch?v=--faa2w_NJo

*Reflection Question

*How do global patterns of atmospheric movement affect local weather?