Transcript Atmosphere And Ozone PPT

skin cancer
Read and annotate
the article “Fish with
Skin Cancer”. Circle
any words you are
unfamiliar with.
Answer the guiding
questions after.
GUIDING QUESTIONS
1. After reading this article, how would you define
ozone?
2. How do you think the article is related to the video?


What does it make you think about?
How does it make you feel?
3. How do you think this article is related to our lesson
today?
4. Why do you think doctors tell us to wear sunscreen?
WHAT IS THE ATMOSPHERE?
•
•
•
•
•
Provides us with oxygen
Absorbs harmful solar radiation
Burns up incoming meteors
Transports and recycles water and nutrients
Moderates climate
WHAT ARE THE LAYERS OF THE ATMOSPHERE?
There are 4 layers (from bottom to top):
•
Troposphere – provides O2, causes weather, thinnest layer
•
Stratosphere – “ozone layer” – protects from UV
•
Mesosphere – low air pressure, low temps
•
Thermosphere
Trick: Tiny Soldiers Make Tents
WHAT IS THE STRATOSPHERIC OZONE?
• Second layer of the atmosphere
• The GOOD  Ozone absorbs the sun’s
harmful UV rays
• UV light can damage living tissue and
cause genetic mutations
• The BAD  pollutants tend to get trapped
and remain in the atmosphere for a long time
What is ozone?
What is ozone?
O3
#4.8 AIM:
H O W D O E S A I R P O L LU T I O N A F F E C T
T H E O Z O N E L AY E R ?
AGENDA
QOD (10)
LESSON:
CFC’S
(15)
ISN’T OZONE A GREENHOUSE GAS?
YES and NO
•
Ozone in the stratosphere blocks UV rays.
WE CANNOT LIVE WITHOUT THIS OZONE
LAYER!
•
Ozone in the troposphere is a greenhouse
gas pollutant that results from
anthropogenic emissions. THIS TYPE OF
OZONE POSES HEALTH THREATS!
•
Can cause respiratory problems
The hole in the ozone
layer
What is ozone?
In the 1960’s,
scientists started
to notice a very
thin part of the
ozone layer above
the Antarctic.
#4.8 AIM:
What do you think is
causing this ozone
depletion?
H O W D O E S A I R P O L LU T I O N A F F E C T
T H E O Z O N E L AY E R ?
AGENDA
QOD (10)
Ozone hole
LESSON:
CFC’S
(15)
CFC’s
What is ozone?
Chloroflourocarbons
(CFC’s) are a type of
air pollutant released
by aerosol spraycans,
refrigerators, and air
conditioners.
#4.8 AIM:
What’s so bad about
turning the ozone layer
into oxygen?
H O W D O E S A I R P O L LU T I O N A F F E C T
T H E O Zozone
O N E L AYby
ER?
CFC’s destroy
turning it into oxygen.
AGENDA
QOD (10)
LESSON:
CFC’S
(15)
#4.8 AIM:
H O W D O E S A I R P O L LU T I O N A F F E C T
T H E O Z O N E L AY E R ?
AGENDA
QOD (10)
LESSON:
CFC’S
(15)
WHY OVER THE ANTARCTIC?
• Hole 3x the size of Australia
• Ozone hole = August- November
• June = cycle begins
• Vortex of cold winds and dark winter create polar
stratospheric clouds that trap CFCs
• September = more sunlight
• Chemical reaction that converts ozone to oxygen (ozone
destruction)
• November = no more vortex
• Ozone rich air mixes in to thinning ozone
WHAT ARE THE EFFECTS OF OZONE
DEPLETION?
•
•
Increased UV radiation
Increased risk of skin cancer for ALL living things
•
•
•
Increased mutations
Increased eye cataracts
Climate Change
including
• Harm to crops
• Harm to ocean phytoplankton which is the base
of all marine food chains
TYPES OF ULTRAVIOLET RADIATION
1. UVA  skin tanning
Less potent that UVB
More of it reaches the surface
2. UVB  sunburns and skin cancer
3. UVC  ozone
 Found only in the stratosphere
Today the ozone
layer is doing
much better…
why?
#4.8 AIM:
H O W D O E S A I R P O L LU T I O N A F F E C T
contributing mostT HtoE O Z O N E L AY E R ?
N2O is now
stratospheric ozone depletion
AGENDA
QOD (10)
LESSON:
CFC’S
(15)
HOW CAN WE REVERSE OZONE DEPLETION?
• Montreal Protocol 
International Treaty (1987)
• Restrict CFC production
• 180 nations agreed to cut
productions by at least 50%
• Today we have reduced CFC
production by over 95%
• Long term recovery of ozone
layer
THROWBACK
Does it seem like
the Montreal
Protocol was more
or less effective
than the Kyoto
protocol? Why or
why not?
WHAT IS CONVECTIVE CIRCULATION?
• Air near Earth’s surface is warmer and moister than air at
higher altitudes
• Convection circulation: Warm air rise = vertical currents
• expands and cools as it rises into lower pressure
• As it cools, it becomes denser and sinks back down
Ever wonder why
the upstairs of a
building is always
hotter? “Warm air
rises and cold air
sinks”
WHY IS VERTICAL MIXING IMPORTANT?
• Temperature Inversion: when a patch of cool air gets
trapped underneath warm air
• the cooler air at the bottom resists vertical mixing
• Vertical mixing pushes ground level pollution upward to
be diluted in the atmosphere
• The 1952 “killer smog” took place when a thermal
inversion trapped pollutants from factories
WHAT CAUSES STORMS?
• Hurricanes form when winds rush into areas of low pressure
where warm, wet air over a tropical ocean is rising
• Tornadoes form when a mass of warm air meets a mass of
cold air and warm air rises quickly, setting a powerful
convection current in motion
QUICK CHECK
Directions: Hold up a finger corresponding to the
letter of the correct answers for the following
questions.
For example: a B corresponds to 2 fingers and a
C corresponds to 3 fingers, etc.
QUESTION 1
THE STRATOSPHERIC OZONE IS NECESSARY TO
OUR SURVIVAL AND PROTECTS US FROM UV
RAYS.
A. TRUE
B. FALSE
QUESTION 2
WHAT IS THE MAIN CULPRIT OF OZONE
DEPLETION?
A. greenhouse gases
B. CFCs
C. UV rays
D. rain
QUESTION 3
What is the name of the protocol that regulated
CFC production in 1987?
A. Kyoto
B. Montreal
C. Kalamazoo
D. Rio de Janeiro