Download chapter 6, unit C

Chapter Six
Unit C
Weather
Lesson 1
How does air pressure
affect weather?
Vocabulary Words
 Air pressure Weather Atmosphere-
Standards
 Students know that Earth’s
atmosphere exerts a pressure that
decreases with distance above
Earth’s surface and that at any point it
exerts this pressure equally in all
directions.
Earth’s atmosphere
 Earth’s atmosphere has



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4 layers:
Thermosphere- hottest at
1,700 *C
Mesosphere- coldest
layer
Stratosphere- contains
the ozone layer
Troposphere- thinnest
layer, where weather
occurs, contains air we
breathe
Atmosphere Facts
 Earth’s atmosphere is made of:
 78% nitrogen
 21% oxygen
 1% other gases
 The atmosphere provides oxygen and
carbon dioxide for humans and plants
 The atmosphere protects Earth from the
harmful rays of the Sun
Air Pressure
 14.7 pounds of air
pressure pressing down
at all times
 Air pressure decreases
as you move up in the
atmosphere
 High elevations = less
air = less air pressure
 Ex. Top of a
mountain, in an
airplane
Measuring Air Pressure
 Mercury barometer
 Aneroid barometer
Lesson 2
Why does air move?
Vocabulary Words
 Jet stream Land breeze Mountain breeze Planetary winds Sea breeze Valley breeze-
Standards
 Students know uneven heating of
Earth causes air movements.
What causes wind?
 The uneven heating
of Earth and different
air pressure = wind
 Wind speed
 Wind blows faster at
higher altitudes
 Mountains and high
buildings causes wind
to slow down
 Winds create energy
 2 types of winds: local
winds & global winds
 4 types of local winds
1. Mountain breeze
2. valley breeze
3. Sea breeze
4. Land breeze
Global Winds
 Always blow in the
same direction
 Effect large areas of
land
 Wind follows a
curved path due to
Earth’s rotation
 Jet Stream- wind
blowing across USA
toward the East
Jet Stream
Windmills provide energy!
Lesson 3
How are weather
forecasts made?
Vocabulary Words
 Air mass Front Meteorologist-
Standards
 Students know how to use weather
maps and data to predict local
weather and know that weather
forecasts depend on many variables.
Weather Predicting
 Thermometer- measure air temperature
 Rain gauge- measure amount of rain fall
 Anemometer- measures wind speed
 Wind vane- measures wind direction
 Barometer- measures air pressure
Weather Instruments
Weather Maps
 What you can find on a weather map:
 Warm fronts
 Cold fronts
 Temperatures
 High and Low pressure
 Sunny or cloudy weather
 Precipitation
 Ex. Rain, sleet, snow, hail
Weather Map
Meteorologist Tools
 Doppler Radar- detects wind speed, can
predict tornados
 Weather balloons- takes weather
instruments high up into the sky, can
predict weather
 Satellites- takes pictures of Earth from
space, can predict hurricanes, looks at
cloud formations
Meteorologist Tools
Lesson 4
What causes storms?
Vocabulary Words
 Blizzard Hurricane Tornado Thunderstorm-
Standards
 Students know the causes and
effects of different types of severe
weather.
Severe Weather
 Thunderstorm
 Caused by warm, moist
air rising
 Creates thunder,
lightning, & rain
 Forms along cold fronts
 Tornado
 Narrow spinning column
of air
 Occurs during a
thunderstorm & where
there is a lot of flat land
Severe Weather
 Blizzard
 Creates heavy winds,
snow, & cold
temperatures
 Common in North East
USA, Great Plains, or
Mountains
 Hurricane
 Most powerful storm
 Winds 74 mph or greater
 Forms over warm water
 Center of the storm = eye
 5 categories of hurricanes
Hurricanes