Atmospheric Movement and Local Weather
*Let’s Review
*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
*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.pbs.org/wgbh/nova/vanished/jetstr_five.html
Abnormally high surface ocean temperatures off the coast of South America
Causes unusual weather patterns across the globe
*El Nino
*A strong surface current
*Begins at the tip of Florida
*Flows up the eastern coastline of the
U.S.
*Crosses the Atlantic Ocean
*Causes warmer climate in NW Europe
*Gulf Stream
*Reflection Question
*Why does the Earth have wind and ocean currents?
*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
*Warm Front- Warm air meets cold air- Slow moving with less severe weather
*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
*Frontal Boundary Simulations
http://www.stevemcentee.com/animation3.html
*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.
*Sea Breeze and Land Breeze
Simulation
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1903/es1903page01.cfm?chapter_no=visualization
*Reflection Question
*How do global patterns of atmospheric movement affect local weather?