1. “The Tale Of Ozone Hole”
IDC-601
ABHISHEK MISHRA
PH14047

2. CONTENTS
• Motivation
• Ozone Chemistry [Stratosphere]
• Historical Timeline
• TOMS dataset / observations
• Lessons Learned

3. DISCRETE LAYERS OF ATMOSPHERE Z[P,T]
IMAGE SOURCE: Howstuffworks
IMAGE SOURCE: Wiki commons
‘SELECTIVE ABSORPTION’ by gases in
Atmosphere
99%[Fix],H2O,
Trace species
Dry, ozone, [m+d]
oxygen, etc.
Difficult to quantify

4. Any object, Temperature > 0 emits Electromagnetic/Thermal Radiation:
[WIDE SPECTRUM OF ENERGIES]
SOLAR ELECTROMAGNETIC SPECTRUM
High Energy Waves Low Energy waves

5. TROPOSPHERE
STRATOSPHERE
MESOSPHERE
OZONE LAYER
“HIGH ENERGY UV
[λ<300nm]
RADIATIONS NEVER
MAKE IT TO THE
EARTH’S SURFACE”
Image Source: Google images
Discovered by
Schoenbien in 1839

6. PHOTODISSOCITION
M: Any Air molecule
This ozone absorbs the harmful UV radiation!!
Although photo dissociation of O2
[Must be Replenished]
CHAPMAN
PROPOSED
COUPLE OF
REACTIONS
[SOURCE]
CHAPMAN’S MECHANISM [1930]

7. Ozone sounding [Source: NOAA Antarctica]
SOURCE
“MISSING SINK”
OVERESTIMATION
25 km
KM

8. NET
The Missing Sinks were identified in the last three decades of research work!!
CATALYTIC
LOSS CYCLES
“PRE-HUMAN
INFLUENCE”
RESERVOIR
MUTUAL
DESTRUCTION

9. They proposed that CFC’s due to their inertness could make it to the Stratosphere and
interact with the catalytic cycles. [Transport Concept]

11. Dr. Joseph Farman
Farman’s Research group and NASA
satellites showed a Expanding
depleted region of ozone in
Antarctica!! [1985]

12. A Rising Concern at that time [Anderson et al., 1989]
It was figured out in a couple of years that the reason was CFC!!

13. PUTTING THE PIECES TOGETHER
RESERVOIR
LOSS OF OZONE
NEW
CATALYTIC
CYCLE
A result of both experimental and Lab results

14. Image courtesy NASA (Mark Schoenberg, GSFC).
PSC’s [Polar Stratospheric Clouds] Jeopardise the Reservoirs
-80 degree centigrade

15. LESSONS LEARNT Source: Prof.V.Sinha
2010
AURA OBSERVATION

16. The Power of Science and Technology!!
Source: Paul Newman Ted talk

17. Hailey Station [1956]
We need to Trust our Data and Work [Honesty]
Dr. Shigeru Chubachi, Meteorological
Research Institute, Japan, measured low
ozone and an ozone hole over Syowa,
Antarctica (reported at Ozone
Commission meeting in Halkidiki, Greece
in Sept 1984)
Source: Paul Newman Ted talk

18. The Significance of Human Beings!!
Source: Wiki Commons

19. Our Strength lies in “UNITY”
The Montreal Protocol
Source: Paul Newman Ted talk

20. Vasudhaiva Kutumbakam
{Rig VEDA}
“THE WORLD IS ONE FAMILY”
THANK YOU

21. References
• Paul Newman Ted talk
• Wallace and Hobbs
• The Ozone Observatory/ the earth observatory [NASA]
• J c Farman, B G Gardiner and J.D Shanklin, [Large losses of ozone in stratosphere {nature 315 -207 (16 May 1985)}
• Mario Molina and Roland [Stratospheric Sinks for CFC’s]
• Johnson et al 1989