Transcript air masses and fronts - Kenston Local Schools

AIR MASSES AND
FRONTS
Chapter 3 Section 1
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Air masses take on the characteristics of the area where they form.
Air mass temperature and moisture are consistent throughout.
•
Warm air forms over tropical regions near the equator.
T- Tropical
•
Cold air forms over polar regions.
P- Polar
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Wet air masses form over water
m- maritime
•
Dry air masses from over land.
c- continental
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• Moisture content is noted by the first
letter.
m – maritime – wet
c – continental – dry
• Temperature is noted by the second
letter.
P – polar – cool
T – tropical - warm
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• mP- maritime polar air mass
• cP – continental polar air mass
• mT – maritime tropical air mass
• cT – continental tropical air mass
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How Air Masses Move
• In the continental U.S. air masses
are moved by:
• prevailing westerlies – west to east
movement
• jet steams.
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•
A front is a boundary between air
masses.
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Four types of fronts and map symbols
1.
2.
3.
4.
Cold front
Warm front
Occluded front
Stationary front
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COLD FRONT
• Cold air mass meets a warm air mass and
pushes the warm air mass out of its way.
• Bring thunderstorms, rain or snow.
• Most tornadoes develop from
• thunderstorms on the edge of a cold front.
• Cold front followed by cooler drier air.
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WARM FRONT
• Warm air mass meets a cold air mass
and pushes the cold air mass out of the
way.
• Brings drizzly precipitation.
• Followed by clear warm weather.
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STATIONARY FRONT
• Cold air meets warm air.
• Not enough force to move either front.
• Many days of cloudy, wet weather.
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OCCLUDED FRONT
• Warm air caught between two cold air
masses.
• 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/me
dina/weather.html
• http://www.classzone.com/books/earth_scien
ce/terc/content/visualizations/es2002/es2002
page01.cfm?chapter_no=visualization
• Click on the above links.
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• Area with lower pressure than surrounding area.
• Winds spiral toward the center.
• Rising air causes stormy weather.
• Hurricanes that from over the Indian Ocean are
called cyclones.
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• Rotation of air around high pressure
center.
• Dry, clear weather
• Winds spiral outward
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Quiz: Take this on the paper provided.
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
me
12. A cold air mass meets a warm air but neither is very strong. They are separated
and many days of wet , cloudy weather occur.
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