Presentation on theme: "Monday January 26, 2009 pg. 51 Happy Chinese New Year! Describe what you know about air masses."— Presentation transcript:
Monday January 26, 2009 pg. 51 Happy Chinese New Year! Describe what you know about air masses.
When air moves over surfaces it takes on the temperature and humidity conditions- - creating an air mass Air masses can extend hundreds or thousands of kilometers
Thursday, January 29, 2009 pg. 53 Based on what we’ve learned, what causes winds to blow?
Winds are the result of uneven heating of earth’s surfaces.
Friday, January 30, 2009 pg. 54 (left side) “Climate is what we expect, weather is what we get.” Write a reaction to this quote.
Why does the wind blow? Winds are the result of the uneven heating of the earth’s surfaces Convection- movement of heat through air or water
Land and Sea Breezes The different rates that land and water change temperature cause wind Low pressure- air warm and light Sea breeze- cool air from the water moves to land, daytime, starts over the water Land breeze- cool land air moves to water, nighttime, starts over the land
Monsoons Monsoons are powerful land and sea breezes Change direction with the seasons India!! Periods of rain- summer- land heats up and pulls moisture from Indian Ocean
Global Winds Winds which form between the equator and the poles Continually forming Move in a particular direction Equator and poles not heated evenly by the sun
Circling the Globe Caused by giant convection currents Warm air at the equator rises and flows toward the poles Cold polar air sinks The radiation of the earth causes these winds to deflect Trade winds- flow toward equator and turn west Westerlies- blow west to east Easterlies- blow east to west Weather changes occur where they meet
Jet Stream Jet stream- long narrow “tubes” of air in the upper troposphere Few hundred kilometers wide Can go 1/2 way around the earth Winds- 200 mph Moves weather in the US from west to east