#### Transcript Describing weather

```Chapter 5, lesson 1
Standards: Sc. 6. E. 7.2, SC.6. E. 7.6,
SC.6.E. 7.7
Learning goal: TSWBAT understand
weather, the variables that affect
weather and how weather is related to
the water cycle.
Weather is the short term changes in the atmosphere in a certain
place at a specific time.
Weather changes quickly.
http://video.nationalgeographic.com/video/101videos/weather-101-sci
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Variables are used to describe the weather.
Temperature and rainfall are more common variables.
Meteorologists ( scientists who study and predict weather) use
many variables to describe a variety of atmospheric changes.
a. Air temperature, air pressure, wind speed, wind direction, humidity, cloud
coverage, and precipitation.
Remember: a VARIABLE is
something that CHANGES
AIR TEMPERATURE
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Measures the kinetic
energy of molecules in
the air.
Molecules in warm air
move faster than
molecules in cold air.
AIR PRESSURE
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Air pressure is the
pressure that a column of
air exerts on the air or a
surface below.
Air pressure decreases as
altitude increases.
Colder air has higher air
pressure than warm air.
Air pressure is measured
with a barometer.
HUMIDITY
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WIND SPEED
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Remember: wind is the
movement of air from
an area of high pressure
to an area of low
pressure.
The tool used to
measure wind speed is
called an anemometer.
Humidity is the amount
of water vapor in the
air.
anemometer
RELATIVE HUMIDITY
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This is the amount of
water vapor present in
the air compared to
how much the air can
hold.
This is shown as a
percentage (%)
Warm air can hold more
water vapor than cold
air.
Relative humidity is measured
with a psychomotor
DEW POINT
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This is the temperature
where air is FULLY
saturated (full of
moisture) because of
decreasing temperature.
Think of a sponge. When
it is full of water, it drips
water. When air becomes
saturated with water
vapor, the water vapor
condenses and forms
water droplets.
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Clouds are water droplets or ice crystals
suspended in the atmosphere.
A cloud that forms near Earth’s surface is
called fog.
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This is water, in liquid or solid form, that falls
from the atmosphere.
http://www.erh.noaa.gov/rnk/Newsletter/W
inter%202004-05/P-Type_files/image005.gif
Snow
Sleet
Freezing rain
rain
Define these words, using your books or
interactive notebooks
 weather
 air pressure
 precipitation
 humidity
 relative humidity
 dew point
 water cycle
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