Transcript Air Masses and their Movements

Air Masses and their
Movements
Chapter 6.3
4 Major types of air masess
• There are 4 major types of air masses that
influence weather in North America:
– A. maritime tropical
– B. maritime polar
– C. continental tropical
– D. continental polar
Air mass
A huge body of air
that has similar
temperature,
humidity, and air
pressure at any
given height.
Tropical
Warm air masses
that form in the
tropics and have
low air pressure.
TROPICAL
Polar
Cold air masses
that form north of
50o north latitude
and south of 50o
south latitude,
with high air
pressure.
POLAR
Maritime
Air masses that
form over
oceans, usually
very humid.
Continental
Air masses that
form over land,
usually drier than
maritime air
masses.
What are the major air masses?
Maritime
tropical
Continental
tropical
Maritime
polar
Continental
polar
Jet streams
Bands of high-speed
winds about 10 km
above Earth’s
surface; generally
blow from west to
east.
I get it! Now I know that the 4 major
types of air masses are…. Pg. 203
1. Maritime tropical
Wet/warm
2. Continental
tropical
Dry/warm
3. Maritime polar
4. Continental polar
Wet/cold
Dry/cold
Maritime Polar:
Cool, humid air masses form over
North Atlantic often pushed out to
sea by westerly winds. These can
also form over the Pacific Ocean
and can bring cool weather to the
west coast.
Continental Polar
These form over Canada
and Alaska, can bring
bitterly cold weather with
low humidity.
Maritime Tropical
Warm, humid air masses that form
over the Gulf of Mexico and the
Atlantic Ocean. Often bring
thunderstorms with heavy rain or
snow. If they form over the Pacific
Ocean they bring hot, humid weather
with summer showers.
Continental Tropical:
Hot, dry air masses that form
mostly in the summer over the
Southwest or N. Mexico. They can
bring hot, dry weather to the great
plains.
Front
The boundary
where air
masses meet.
Weather @ the Front pgs. 204-205
Clouds, many
days of precipitation
Clouds, heavy
precipitation
Clouds, many
days of precipitation
Clouds, precipitation
Occluded
Cut off, as in a
front where a
warm air mass is
caught between
two cooler air
masses. Most
complex of the
different fronts
What are the main types of fronts?
Cold Front 
Occluded 
Front
 Warm Front
Stationary
Front
What weather do cyclones and
anticyclones bring?
Cyclones and decreasing air
pressure are associated
with …
clouds, wind, and
precipitation.
Anticyclones are associated
with …
dry, clear weather.
Cyclone
A swirling center
of low air
pressure.
Anticyclone
High-pressure
centers of dry
air.
Air Masses and Their Movements
Cyclones and Anticyclones
Which image is a cyclone and which is an anticyclone? What is the air
motion direction of each?
Cyclone
Anticyclone
Air Masses and Their Movements
Pg. 207
Which circles are low-pressure centers and which are high-pressure
centers?
L
H
L
H
I get it! Now I know that… pg. 207
Cyclones cause….
Anticyclones cause…
clouds, wind, and
precipitation
dry, clear weather