Presentation On

PRESENTATION ON OZONE LAYER & ITS DEPLETION

PRESENTED BY NAME 1)RUJUTA KULKARNI

ROLLNO. 37

2)SANKET KULKARNI

38

3)PALLAVI KUTE

39

4)AMAN LAD

40

CONTENTS • • • • • • • • • •

what is ozone layer? Origin of ozone layer. About ozone layer. UV rays &their harmful effects. Importance of ozone layer. Depletion of ozone layer. Effects of ozone depletion. Ozone Hole. Causes for ozone hole. What you can do to protect ozone layer?

What is the ozone layer? • The ozone layer is a deep layer in the stratosphere, encircling the Earth, that has large amounts of ozone in it. The layer shields the entire Earth from much of the harmful ultraviolet radiation that comes from the sun.

ORIGIN OF OZONE LAYER 

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OZONE LAYER IS FORMED BY ABSORPTION OF UV RAYS IN STRATOSPHERE AT A HEIGHT OF 16km FROM EARTH SURFACE. IT EXTENDS FROM 16 TO 23km FROM EARTH SURFACE. OZONE CONTAINS 3 ATOMS OF OXYGEN (O3)

ABOUT OZONE LAYER 

The thickness of Ozone layer varies across different regions, it is less dense above the equator and this density increases increases while moving towards the poles. The amount also varies with season, as the amount is more in winters as compared to summers.

ULTRAVIOLET RAYS &THEIR HARMFUL EFFECTS 

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Ultraviolet ray is an electromagnetic radiation that has wavelength smaller than that of visible light . Direct exposure to UV rays cause: Sunbum Skin cancer Premature ageing of skin

ULTRAVIOLET RAYS

IMPORTANCE OF OZONE LAYER

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It is Ozone layer that absorbs 93 % of the harmful, high frequency Ultraviolet radiations

DEPLETION OF OZONE LAYER 

The Ozone molecules (O3) can be damaged by free radicals like hydroxyl, chlorine, bromine, and nitric oxide .

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There are certain artificial compounds like chlorofluorocarbons and bromofluorocarbons that have tendencies to damage Ozone molecules.

EFFECTS OF OZONE DEPLETION Effects on Human Health: causes skin diseases. Effects on plants: plant growth is affected by UVB radiations. Effects on Marine Ecosystems: damage to early developmental stages of fish,crabs,amphibians. It also affects biogeochemical cycles.

OZONE HOLE  IT IS SEEN NEAR ANTARCTICA.

Causes for the Ozone Hole 

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Chlorofluorocarbons or CFCs are used in refrigerants and coolants. CFCs are typically heavier than air, but they can ascend in the atmosphere in a process that takes 2-5 years. Once in the stratosphere, UV radiation break apart the CFC molecules into dangerous chlorine compounds which are known Ozone Depleting Substances (ODS).

What you can do to protect ozone layer? • Encourage people with cars to have their air conditioners fixed by mechanics who are certified to handle. • We should discover new methods to replace CFC’s

THANK YOU VERY MUCH !