1. Air Masses What is an air mass?

2. Air Mass  An air mass is a large volume of air defined by its temperature and water vapor content. air temperaturewater vaporair temperaturewater vapor  The weather characteristics are determined by the geographical origin (Birth place) of the air mass.

3. Humidity- First Name  Air masses that form over the ocean are called maritime air masses. They are MOIST (Maritime=Moist) They are MOIST (Maritime=Moist)  Air masses that form over the land are called continental air masses They are dry (Continental=continent/land) They are dry (Continental=continent/land)

4. Temperature- Last Name  Air Masses that form near the Poles are known as polar air masses. They are cold (Think Polar Bears!) They are cold (Think Polar Bears!)  Air Masses that form near the tropics are known as tropical air masses. Tropical air is warm (Think tropical vacation!) Tropical air is warm (Think tropical vacation!)  Air Masses that form at the North Pole are known as an arctic air mass.  (Arctic air is FREEZING)

5. The name of an air mass has TWO PARTS  The first part (first name) tells us either maritime or continental. (humidity)  The second part (last name) tells us tropical or arctic, polar. (temperature)

6. Air Mass  First Name Maritime (ocean) Maritime (ocean) Continental (land) Continental (land)  Last Name Arctic (freezing) Polar (cold) Tropical (warm) http://video.about.com/weather/Types-of-Air-Masses.htm

7. Key Terms  Air mass- large area of air has the same temp and humidity (amount of moisture)  Continental air mass- Air mass over land  Maritime air mass- air mass over oceans  Polar air mass- air mass over cold regions  Tropical air mass- air mass over warm regions  Arctic air mass- air mass over the Poles

8. What type of an air mass would it be if…  It started on land and near the North Pole?  It started near the equator in Mexico?  It started in Florida?  It started over the Atlantic Ocean in the North east?  It started near the South Pole over Antarctica?  Can you make up a “What type question”????

9. http://usatoday30.usatoday.com/weather/tg/wamsorce/wamsorce.htm