2. The ozone layer is a layer in Earth's
atmosphere containing relatively high
concentrations of ozone
The ozone layer was discovered in 1913
by the French physicists Charles
Fabry and Henri Buisson.
What is Ozone Layer?
3. Although the concentration of the ozone in
the ozone layer is very small, it is vitally
important to life because it absorbs
biologically harmful ultraviolet (UV)
radiation coming from the sun.
Why it is important for Earth?
4. In 1978, the United
States, Canada and Norway enacted bans
on CFC-containing aerosol sprays that are
thought to damage the ozone layer. The
European Community rejected an
analogous proposal to do the same.
Regulation
14. The atmosphere
The
atmosphere is
a layer around
the Earth that
mantains its
gravity. And it
also protects
life in Earth by
absorbing
many sunrays.
15. The ozone layer is inside the Atmosphere, in the stratosphere.
Which is after the troposphere and before the Mesosphere, the
Ionosphere (thermosphere) and de Exosphere.
The ozone layer in the atmosphere
18. The ozone layer is a layer which protects
the Earth from the UV (ultra violet)
radiations which are originated in the sun.
This UV radiations can cause skin
cancer, suppressions to the immune
system and eye cataract.
19. Today, the ozone layer is being destructed
by the contamination produced in the
Earth. As a consequence, many
phenomena such as Global Warming or
the Water Crisis are causing great
damages on the Earth and in society.
23. Ozone depletion describes two distinct
but related phenomena observed since
the late 1970s: a steady decline of about
4% per decade in the total volume
of ozone in Earth's
stratosphere (the ozone layer), and a
much larger springtime decrease in
stratospheric ozone over Earth's polar
regions. The latter phenomenon is
referred to as the ozone hole.
Ozone Depletion
24. Chlorofluorocarbons (CFCs) and other
halogenated ozone depleting substances
(ODS) are mainly responsible for man-
made chemical ozone depletion. The total
amount of
effective halogens (chlorine and bromine)
in the stratosphere can be calculated and
are known as the equivalent effective
stratospheric chlorine (EESC).
Chemicals in the
atmosphere
CFCs= Chemistry chlorofluorocarbon, any of a class of synthetic
compounds of carbon, hydrogen, chlorine, and fluorine formerly
used as refrigerants and aerosol propellants and known to be
harmful to the ozone layer.
25.
26. As explained above, the primary cause of
ozone depletion is the presence of chlorine-
containing source gases (primarily CFCs and
related halocarbons). In the presence of UV
light, these gases dissociate, releasing
chlorine atoms, which then go on to catalyze
ozone destruction. The Cl-catalyzed ozone
depletion can take place in the gas
phase, but it is dramatically enhanced in the
presence ofpolar stratospheric clouds (PSCs).
Ozone hole and it causes
27. Since the ozone layer absorbs UVB ultraviolet
light from the sun, ozone layer depletion is
expected to increase surface UVB levels, which
could lead to damage, including increase in skin
cancer. This was the reason for the Montreal
Protocol. Although decreases in stratospheric
ozone are well-tied to CFCs and there are good
theoretical reasons to believe that decreases in
ozone will lead to increases in surface UVB, there
is no direct observational evidence linking ozone
depletion to higher incidence of skin cancer and
eye damage in human beings.
Consequences of ozone layer
depletion
28. http://www.youtube.com/watch?v=UfyOJ
b1widI
http://www.educaplay.com/es/recursos
educativos/675706/ozone_layer.htm
http://www.youtube.com/watch?v=qUf
VMogIdr8
Link of videos and an excersice:
