air masses. changes in weather are caused by the movement of air masses

Air Masses

Changes in weather are caused by the movement of air masses.

An AIR MASS is a very large volume or block of air w/ similar temp. & humidity (moisture) throughout.

An air mass’s humidity & temp. depend on the area where it formed or its source region.

Therefore you name air masses to describe their temperature & humidity.

Moisture descriptions Temp. descriptionsContinental (dry) Polar

Maritime (wetter) Tropical

The 4 major masses are:The 4 major masses are:

Type/NameWhere if Forms

Temperature

Humidity

Maritime Polar

Maritime Tropical

Continental Polar

Continental Tropical

Air masses and source regions for North American

Air masses and source regions for the world

AIR FRONTS

When two different air

masses meet & don’t mix they make fronts.

Fronts bringing changes in the

weather & possibly precipitation.

There are four types of fronts

• Cold

• Warm

• Stationary

• Occluded

https://s-media-cache-ak0.pinimg.com/originals/80/6d/36/806d36c0404d3afec7f55b24615a8092.jpg

After the frontthe weather usually is clear and sunny