Download 17.1 Structure of the Atmosphere

Aim: How is our atmosphere
structured?
Do Now:
Watch the
video
Atmosphere:
- the layers of gas that surrounding Earth.
I. Changes in Pressure
- Atmospheric pressure is
the weight of the air
molecules above you.
- measured with a barometer (units = millibars)
ESRT
Page 13
- The atmosphere thins as you travel away
from Earth’s surface. (less molecules)
Where would you expect to find the most pressure?
At sea level (1 atm)
WHY?
Where would you expect to find the least pressure?
On a mountain peak
WHY?
- At sea level, there is 1 atm of pressure.
(this is all the gas molecules are above your head
weighing down on you)
- Pressure is highest at sea
level = 1.0 atm.
- As altitude increases air
pressure decreases.
- At the top of the
Stratosphere the
pressure comes close to
0 atm.
Sea level
ESRT page 14
Why does the
pressure
approach zero
as altitude
increases?
- A decrease in
gas molecules
II. Changes in Temperature:
- a measure of the average
kinetic energy in a substance.
(particle movement)
- measured with a thermometer
- Units of temperature include
• Celsius
• Fahrenheit
• Kelvin
ESRT p. 13
- Changes in
temperatures help
indicate the different
layers of the atmosphere.
Describe the temperature
change with altitude in
the:
Troposphere: INDIRECT
Stratosphere: DIRECT
ESRT page 14
III. Layers of the Atmosphere
* Between each
layer is a
boundary that
separates the
layers called a
“pause”.
What features
do you notice
take place in
the different
layers of the
atmosphere?
1. Troposphere:
(where we live!)
–
90% of all gases
–
all clouds and
weather
–
Temp. decreases
as altitude
increases
Describe the
relationship between
temperature and altitude
in the Troposphere.
What is the lowest
temperature in the
Troposphere? -550C
2. Stratosphere:
– Contains the Ozone
Layer (blocks dangerous
ultraviolet radiation).
– Temperature
increases as altitude
increases.
Describe the
relationship between
temperature and altitude
in the Stratosphere.
What is the highest
temperature in the
stratosphere?
- 00C
– Contains Jet Streams;
which are high speed
winds that influence
our daily weather.
3. Mesosphere
– Meteoroids burn up
due to friction with
air particles forming
“shooting stars”.
– Temp. decreases as
altitude increases.
Describe
the
At what
altitude
does
relationship
between
the Mesosphere
temperature
begin? and
-
altitude in the
30mi or 50km
troposphere.
4. Thermosphere
– Temperature
increases as
altitude
increases.
– Contains the
ionosphere
(charged
particles)
creating the
“Aurora’s” or
The Northern &
Southern Lights
Describe the relationship
between temperature and
altitude in the
troposphere.
Aurora (Northern Lights)
5. Exosphere
• Is the uppermost layer
of the atmosphere.
• Contains Earth’s
Satellites
• Last layer before
space
ESRT page 14
Closure: