Transcript What are air masses?

What are air masses?
Lesson 3
Air Masses
• Huge body of air
– Same temperature
– Same humidity
– Heated or cooled by area it is over
• Humidity
– Amount of water vapor in the air
Weather-result of how air, water
and temperature interact.
• Caused by the way air masses
– Move
– Interact
• Weather is predicted by:
– Where air mass is moving
– What air masses it will meet
– How it will meet them.
Fronts-an area where two air masses meet
• Cold fronts
– Moving cold air mass meets a warm air mass
– Move faster than warm fronts
• Cold air
– Denser than warm air
– Sinks under warm air
– Warm air pushed up
– Water vapor in cooling air
condenses into clouds.
• Usually brings
– winds
– Heavy precipitation
• Warm Fronts
– Warm air runs into a cold front
– Warm front develops
– Warm air slides over cold air
– Less dense than cold air, and rises
– Water vapor forms clouds
– Affects a larger area
– Brings steady, long lasting precipitation
Cloud Formation
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Sun warms bodies of water
Heated water evaporates
Sun wars the air holding water vapor
Air rises and cools
Vapor become tiny water droplets and ice
crystals (clouds)
Cloud Types
• Cumulus
– Thick, white and puffy
– Fair and good weather
– High in the sky
• Stratus
– Flat layers
– Close to earth’s surface
– Rain or snow
• Cirrus
– Feathery
– High in the atmosphere
– Warm weather
Alto-very high clouds
Nimbo-rain bearing
(producing)
fog
Cumulus
Stratus
Cirrus