Download Air Masses and Fronts

Air Masses and Fronts
Page 128
•Climate is what we expect, weather is
what we get
• Mark Twain
Air Mass page 129
• A large body of air throughout which
temperature and moisture content are similar
• The amount of solar energy received and
location of formation determines the
temperature and moisture content in the air
mass.
Types of Air Masses-Moisture
1. Continental Air Masses – form over land masses.
Dry (not a lot of water).
2. Maritime Air Masses – form over oceans or other
large bodies of water. Wet (moisture amount
depends on solar energy).
Types of Air Masses-Temperature
3. Tropical Air Masses – form in warm regions, contain
hot or warm air (lots of solar energy)
4. Polar Air Masses – form in cold regions, contain
cold or cooler air. (less solar energy)
Always has a moisture and temperature
indicator!
Air masses
Source Region
Type of air
Symbol
Continental
Dry
c
Maritime
Moist
m
Tropical
Warm
T
Polar
Cold
P
Front page 130
• A boundary between air masses, where the air does not usually mix
• The differences in temperature and pressure cause clouds and precipitation
to form at fronts
• We map these boundaries to find out what the weather will be like in
different areas of the world
Cold Front
• The front edge of a moving mass of cold air that
pushes beneath a warmer air mass like a wedge.
• Heavy precipitation or thunderstorms form at this
boundary and it brings colder weather
Warm Front
• The front edge of an advancing warm air mass that replaces
colder air with warmer air
• Produces precipitation over a large area, followed by clear
skies
Stationary Front
• The front edge of two air masses that meet and move
either very slowly or not at all
• Varied weather, but usually clouds and precipitation
Occluded Front
• Cold air mass that overtakes a
warm air mass and lifts the
warm air mass off the ground
and over another cold air mass
• Weather is variable with some
areas stormy and others not