Download Air Masses

Air Masses
• Differences in air
pressure are caused
by unequal heating of
Earth’s surface
– creates wind patterns
– Deflects in a curved
path because of the
Coriolis effect
Review
• Along the surface,
air moves from
areas of high
pressure to areas of
low pressure
– Poles to Equator
• At high altitudes,
air moves from the
equator to the poles
Target #9- I can
describe how air
masses form
• When air is stationary, or
moves slowly, the air takes
on the temperature and
humidity of a region
• Air Mass: a
large body of
air throughout
which
temperature
and moisture
content are
similar
Target #10- I can
define air mass
Target #11- I can describe how
air masses are classified
• Air masses are classified
according to their source
regions
–Source region: determine
temperature and humidity of an
air mass
• Polar areas produce cold and dry
air masses
• Tropical areas produce warm moist
air masses
Target #12 I can
differentiate
between
continental and
maritime air
masses
• Continental: air masses
that form over land
– Form over large land
masses
– Low humidity
– Brings dry weather
– Continental Polar- cold
and dry
• Symbol: cP
– Continental tropicalwarm and dry
• Symbol: cT
• Maritime: air masses that
form over oceans
– Form over large bodies of
water
– Higher humidity than
continental air
– Commonly bring
precipitation when
travelling over land
– Maritime polar- moist and
cold
• Symbol mP
– Maritime tropical- moist
and warm
• Symbol mT
Target #13- I can identify North
American air masses on a map
• North American Air Masses
– Continental Tropical
• Form in the southwestern U.S.
• Brings hot, dry weather
– Maritime Tropical
• Form over the Atlantic Ocean
• Brings humid weather to eastern U.S.
– Continental Polar
• Form in Canada
• Bring cool dry weather to northern U.S.
– Maritime Polar
• Forms in northern Pacific & Atlantic Oceans
• Brings rain, snow, and fog to the Pacific Northwest
and New England
• New Jersey is
about halfway
between the
equator and the
North Pole
–Geographic location
results in highly
variable daily
weather
Target #14- I can
summarize how
the air masses
over New
England
influence New
Jersey weather
• The Garden State is
166 miles long, and is
65 miles at its widest
point
– There is a marked
difference in climate
between Wildwood and
Ocean City in the south
and High Point and
Stokes State Forest in
the north
• The prevailing winds in
NJ travel west to east
– A part of the westerlies
wind belt
– Can shift north or south
which influences the
weather
• If shifting south,
continental polar air
brings colder
temperatures with
potential for snow
• If shifting north,
maritime tropical air bring
hot humid weather and
potential for rain
• Current Satellite Maps
• In northern NJ:
– Average annual precipitation: ~51in
– Snowfall season: Oct to April
– Precipitation comes from storms coming
from the Mississippi Valley, Great Lakes,
and from southern Canada.
– The mountains also influence the formation
of precipitation
– The heat retained by the city also
influences the types of weather produced
Analysis Question
• How do temperature and humidity
change when a maritime tropical air
mass is replaced by a continental polar
air mass?