Name: _________________________________
Core: ______
Layers of the Atmosphere – August 3, 2015
There are 5 layers of the atmosphere (Troposphere  Stratosphere  Mesosphere  Thermosphere  Exosphere).
TROPOSPHERE (4 – 12 miles) = THE LAYER THAT YOU LIVE IN!
 All weather and the air you breathe! The lowest and most important layer.
 Contains 90% of all the gas molecules in the atmosphere! Why? _____________________________________
 Temperature is highest at the surface of the earth and decreases with altitude.
•
The Sun sends solar radiation through the
atmosphere in the form of electromagnetic
waves.
•
Rock, soil, and water absorbs the Sun’s light
and radiates it back as heat.
•
As you move further from the ground, you
are moving further from the source of this
reflective heat.
•
Also, there are less molecules in the air as you increase in altitude.
•
Less molecules = less collisions = less heat
STRATOSPHERE (20 – 31 miles high)= THE SECOND LAYER
 Contains the ozone layer that helps to trap heat in the atmosphere.
 As you increase in altitude, temperature increases.
 Warm air sits above cool air = stable = no weather.
 How is this different than the troposphere? _______________________________________________________
 Why do planes fly in the stratosphere? Answer: When they leave the troposphere and enter the stratosphere,
fuel costs are lower because there is less friction due to the lower air density…there’s also less turbulence.
MESOSPHERE (31 – 53 miles high) = THE MIDDLE LAYER
 Temperature decreases with altitude (heat is from the stratosphere)
 Extremely low density of molecules
 Meteor showers occur here.
 The pressure is so low that liquids would boil at normal body temperature.
 Your blood would boil without a space suit!
 Thinking Question: Does water boil faster at sea level or in the mountains? ______________________
THERMOSPHERE (53 – 430 miles high) = THE FOURTH LAYER
 Temperature increases as you increase in altitude.
 Very low density of molecules
EXOSPHERE (430 miles to outer space)
 Outermost layer of the atmosphere.
SUN


Source of all of the energy on Earth.
Energy from the sun must pass through the different layers of the atmosphere before it hits the surface.
TEMPERATURE PATTERN
•
The atmosphere is divided into different layers based on the shifts in the temperature increasing or decreasing
with altitude. It is a pattern!!
•
Thermosphere: As altitude increases, temperature increases
•
Mesosphere: As altitude increases, temperature decreases
•
Stratosphere: As altitude increases, temperature increases
•
Troposphere: As altitude increases, temperature decreases
AIR PRESSURE AND DENSITY

Air pressure and density DECREASE as you increase in altitude
(less air the further up you go!).

Density: the amount of molecules (mass) in a given volume of
substance.

Gravity pulls molecules down to Earth!

Air pressure (atmospheric pressure): = The force of the air
weighing down over a unit of area.

Air molecules constantly bounce off each other and push on all
the surfaces they touch.

The amount of pressure exerted by our atmosphere is about 14.7
pounds per square inch.
Why don’t you feel it? All the air and liquids in your body
push outward with the same pressure!


Barometer = any instrument that measures air pressure; “bar”
refers to “air pressure”
Isobars = = a line on a map connecting points having the same atmospheric pressure.