Weather

1
Weather Climate

• The Air Around Us

2
What is Air? Its Got Us Covered

• Air is made up of matter- it takes up space.
• Air is a mixture of gases- tiny particles in
  motion.
• Air is made up of nitrogen, oxygen, carbon
  dioxide, water vapor.

3
Properties of Air

• Because air has mass, it also has other
  properties, including density and pressure.
• Density-  the amount of mass in a given volume of
  air
• You can calculate density by dividing mass by
  volume
• Pressure  The force pushing on an area or surface

4

• Air pressure is the result of the weight of a
  column of air pushing down on an area.
• The weight of the column of air above your desk
  is about the same as the weight of a large school
  bus!
• molecules in air push in all directionsdown, up,
  and sideways

5
Measuring Air Pressure

• barometer is an instrument that is used to
  measure changes in air pressure
• There are two kinds of barometers mercury
  barometers and aneroid barometers.

6
Mercury Barometers

• consists of a glass tube open at the bottom end
  and partially filled with mercury.
• Air pressure pushes down on the surface of the
  mercury in the dish, causing the mercury in the
  tube to rise.

7
Aneroid Barometers  

• aneroid means without liquid.
• has an airtight metal chamber
• Changes in air pressure cause the walls of the
  airtight metal chamber to flex in and out.
• The needle on the dial indicates the air
  pressure.

8
Earths Blanket Of Air

• Atmosphere- A blanket of air that always
  surrounds Earth.
• The atmosphere is made up of 4 layers
• -Troposphere (its where we live)
• -Stratosphere
• -Mesosphere
• -Thermosphere

9
Sometimes Its a Wet Blanket

• Weather- The condition of the atmosphere at a
  certain place and time.
• When talking about weather, you are actually
  describing what is happening in the atmosphere.
• Weather is constantly changing.
• Without the atmosphere, there would be no
  weather!

10
Not Too Warm, Not Too Cold

• A Gardeners
• Greenhouse
• Sun rays enter greenhouse and strike surfaces.
• Heated air rises
• Glass traps heat inside.

11
Earths Greenhouse

• Earths atmosphere acts like a greenhouse
• Sun passes through the atmosphere and heats land
  water.
• Some heat goes back into the atmosphere.
• Heat trapped by water vapor, carbon dioxide,
  other gases will be sent back to Earth.

12
Feeling the Air

• Dark colored materials heat up quicker than light
  colored materials. So air above dark colored
  surfaces heats up quicker.
• When air is warmed the particles spread out.
• Warm air becomes lighter rises. The cooler air
  sinks.
• This movement of air is called WIND.

13
Land Sea Breezes

• Land Breeze
• (cool land/warm sea)
• Cool air over land moves out toward the water and
  takes the place of rising air.
• Warm air over the water rises.

• Sea Breeze
• (warm land/cool sea)
• Warm air over the land rises.
• Cool air over the water moves toward land and
  takes the place of the warmer air that has risen.