BELL WORK 11/09
What is the difference between
humidity and relative humidity?
WEATHER PATTERNS
Chapter 5.2- 5.3
HIGH-PRESSURE SYSTEMS
A high-pressure
system is a large body
of circulating air with
high pressure at
center and lower
pressure outside
LOW-PRESSURE SYSTEM
A low-pressure
system is a large
body of circulating
air with low pressure
at center and
higher pressure
outside
AIR MASSES
Air
masses- large bodies of air with distinct
temperature and moisture characteristics.
Continental
Maritime
air masses form over land.
masses form over water.
FIVE MAIN AIR MASSES ACROSS N. AMERICA
Ex: Artic air masses- bitterly cold, dry air (-40C during
winter)
FRONTS
A
weather front is a boundary between
two air masses.
Changes
fronts.
in weather are common at
Examples:
 Cold,
Warm, stationary, and occluded
DO NOT TAKE NOTES ON THE FOLLOWING
4 SLIDES!
*ANIMATION
BELL WORK 11/10
Differentiate between a cold front, warm
front, and occluded front.
COLD FRONT
When
a colder air
mass moves toward
a warmer air mass,
a cold front forms.
Brings
bad weather
and cool
temperature
WARM FRONT
A
warm front forms
when lighter,
warmer air moves
toward colder,
heavier air.
Weather
will be
warmer and more
humid.
STATIONARY FRONT
When the
boundary
between two air
masses stalls, the
front is called a
stationary front.
OCCLUDED FRONT
When a fast-moving
cold front catches up
with a slow-moving
warm front, an
occluded or blocked
front forms.
 Usually
brings
precipitation!
WEATHER FORECASTS
MEASURING THE WEATHER
A
surface report describes a set of weather
measurements made on Earth’s surface.
An
upper-air report describes wind, temperature,
and humidity conditions above Earth’s surface.
 Radar
Doppler
and Doppler radar
radar is a specialized type of radar that
can detect precipitation (radar) as well as the
movement of small particles, which can be used
to approximate wind speed.
WEATHER MAPS
**Weather maps contain symbols that provide
information about the weather.
WEATHER MAPS
A
station model uses observations from surface reports
and upper-air reports.
 Isobars
are lines that connect all places on a map where
pressure has the same value.
 Isobars
show the location of high- and low-pressure
systems and provide information about wind speed.
SEVERE WEATHER
SEVERE WEATHER
A
tornado is a violent, whirling column of air in
contact with the ground.
An
intense tropical storm with winds exceeding
119 km/h is a hurricane.
A
blizzard is a violent winter storm characterized
by freezing temperatures, strong winds, and
blowing snow.
FACTORS THAT AFFECT CLIMATE
Climate- long-term average weather conditions
of a particular region
Climate may be affected by:
• Latitude
• Altitude
• Location (mountains and large bodies of
water)
FACTORS THAT AFFECT CLIMATE
 Latitude- distance from equator
• As latitude increases, the intensity of solar
energy decreases.
Draw this!
FACTORS THAT AFFECT CLIMATE
Climate Zones
 Latitude Zones
• Tropical zone- The sun’s rays are most intense
and the temperatures are always WARM
• Temperate zones-The sun’s rays strike Earth at a
smaller angle than near the equator= MODERATE
• Polar zones- The sun’s rays strike Earth at a
very small angle in the polar zones= COLD
FACTORS THAT AFFECT CLIMATE
 Altitude
• The higher the elevation is, the colder the
climate.
 Location
• Mountains play an important role in the amount of
precipitation that falls
• Rain shadow effect- an area of LOW rainfall
on the downwind side of a mountain
THE RAIN SHADOW EFFECT
FACTORS THAT AFFECT CLIMATE
 Water of Water
• The temperature of the water body influences the
temperature of the air above it.
• The temperature of water changes slowly so
climates near coastlines have more moderate
temperatures than those inland
 Global winds
• Distribute heat and moisture around Earth
THINK ABOUT IT…
Which of the 2 cities, located at
the same latitude, would have
the hotter summer: the one
situated on the coast or the one
situated further inland?