AIR MASSES AND FRONTS Chapter 16 Section 2

Air Masses Air masses take on the characteristics of the area over which they form. The temperature and moisture are consistent throughout.

Air Masses Warm air forms over tropical regions near the equator. T- Tropical Cold air forms over polar regions. P- Polar Wet air masses form over water m- maritime Dry air masses from over land. c- continental

Air Masses Continental Polar cP

Air masses Moisture content is noted by the first letter. m – maritime – wet c – continental – dry

Air Masses Temperature is noted by the second letter. P – polar – cool T – tropical - warm

Continental Polar cP

Air Masses mP- maritime polar air mass cP – continental polar air mass mT – maritime tropical air mass cT – continental polar air mass

Fronts A front is a boundary between air masses.

Fronts Cold front Warm front Occluded front Stationary front Four types of fronts and map symbols Cold front Warm front Occluded front Stationary front

COLD FRONT What happens? Cold air mass meets a warm air mass and pushes the warm air mass out of its way. What kind of weather do they bring? Bring thunderstorms, rain or snow, followed by cooler, drier air. Most tornadoes develop from thunderstorms on the edge of a cold front.

WARM FRONT What happens? Warm air mass meets a cold air mass and pushes the cold air mass out of the way. What kind of weather does it bring? Brings drizzly precipitation, followed by clear warm weather

OCCLUDED FRONT What happens? Warm air caught between two cold air masses. What kind of weather does it bring? Brings cool temperatures with large amounts of rain or snow

STATIONARY FRONT What happens? Cold air meets warm air, without enough force to move either front. What kind of weather does it bring? Many days of cloudy, wet weather

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.

Cyclone 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. Tornadoes are also called cyclones; they just aren’t tropical in nature.

Anticyclone Rotation of air around high pressure center. Dry, clear weather

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.

Quiz: Take this on the paper provided. 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. 10. A warm air mass meets and pushes a cold air mass out of the way. 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.