AIR MASSES AND FRONTS

By: Ms. Nail

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An air mass is a large body of air that develops over a particular region.• Warm air forms over tropical regions near the equator. Has low air pressure. T- Tropical

• Cold air forms over polar regions. Has high air pressure P- Polar

• Wet air masses form over oceans. m- maritime

• Dry air masses from over land. c- continental

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• Moisture content is noted by the first letter.

m – maritime – wetc – continental – dry• Temperature is noted by the second letter.P – polar – coolT – tropical - warm

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• mP- maritime polar air mass

• cP – continental polar air mass

• mT – maritime tropical air mass

• cT – continental polar air mass

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• A front is a boundary between air masses.

• Four types of fronts and map symbols

1. Cold front2. Warm front3. Occluded front4. Stationary front

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COLD FRONT

• What is a cold front? A cold front forms when a cold air mass pushes under a warm air mass.

• Bring thunderstorms, rain or snow.

• This produces cumulonimbus clouds.

• Cold front followed by cooler drier air.

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WARM FRONT

• What is a warm front? A warm front forms when a warm air mass moves up and over a cold air mass.

• This produces stratus and cirrus clouds.

• Brings drizzly precipitation.

• Followed by clear warm weather.

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STATIONARY FRONT

• What is a stationary front? A stationary front forms when a warm air mass and a cold air mass meets but neither advances.

• Many days of cloudy, wet weather.

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OCCLUDED FRONT

• What is an occluded front? An occluded front forms when a fast moving cold air mass overtakes a slower warm air mass.

• Brings cool temperatures with large amounts of rain or snow

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Cold Front, Warm Front and Occluded Front Animation

• http://www.3villagecsd.k12.ny.us/Murphy/medina/weather.html

• http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualization

• Click on the above links.

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1. Describe a maritime polar (mP) air mass, in terms of moisture and temperature.2. What is the name of an air mass that forms over water?3. What is the name of an air mass that forms over land?4. What is the name of an air mass that forms in a cold region?5. What is the name of an air mass that forms in a warm region?6. Describe a continental tropical (cT) air mass, Moisture and temperature.7. The boundary between two air masses is called a ______________________.8. A cold air mass meets and pushes a warm air mass out of the way.What type of front am I?9. A warm air mass is trapped between to cold air masses. What type of front am I?10. A warm air mass meets and pushes a cold air mass out of the way. What type of front am I?11. I am a front that brings drizzly rain and am followed by warm clear weather. Name

me12. A cold air mass meets a warm air but neither is very strong. They are separated

and many days of wet , cloudy weather occur.

Quiz: Take this on the paper provided.

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