erosion of ozone layer. erosion of ozone layer position of ozone layer : ozone layer is mainly...

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Erosion of Ozone Layer

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Page 1: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Erosion of Ozone Layer

Page 2: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Erosion of Ozone layer

Page 3: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Position of ozone layer:

Ozone layer is mainly locate at height 20:40Km above sea level in the lower part of

stratosphere layer .

Page 4: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Why? Because it is the first layer of atmospheric envelope which faces ultraviolet radiations emitted from the sun, and also it contains suitable amount of oxygen

gas.

Page 5: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Structure of Ozone layer: Ozone layer is composed of Ozone gas (O3) which consists of three oxygen

atoms .

Page 6: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

How? When ultraviolet rays pass from oxygen molecule it break the covalent bond and become one atom then it combine with anther molecule to make (O3)

molecule .

Page 7: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Ultraviolet rays

UV

O2 O + OUV

Page 8: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

O + O2 O3

Page 9: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Thickness of Ozone layerThe English scientist

DOBSON postulated that the thickness of the Ozone layer is compressed into 3mm. Only if it were under the normal pressure and 0 C temperature (STP).

Page 10: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The scientists took “DOBSON” as a measuring unit of degree for Ozone layer (100 DOBSON unit (DU) is defined as 1mm. Thickness)

so

The thickness of Ozone layer=300DU.

Page 11: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The importance of

Ozone layer: There are three types of UV rays that differ in wavelength and effect:

Page 12: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Types of UVrays

Near UVRays

(UV-A)

Medium UVRays

(UV-B)

Far UVRays

(UV-C )

Page 13: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Living organisms

Harmful effects

Human: •Increase the rate of skin cancer• cataract

Amphibians: •Spoil eggs

Marine organisms:

•Death of plankton which is the main nutrient of small marine creature.

Terrestrial plants:

•Upset the photosynthesis process

Page 14: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Erosion in September! Since 1978, scientists have noticed

that there was erosion in Ozone layer above the South pole ,and it

increase in September : Why?

Page 15: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Because all pollutants assemble as black cloud and are pushed by wind towards south pole making Ozone depletions increase

from year to year .

Page 16: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Pollutant of Ozone layer: 1. Chlorofluorocarbon (CFC).

2. Methyl bromide gas.3. Halons.4. Nitrogen oxides.

Page 17: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Chlorofluorocarbon (CFC)They are compounds known

as Freon, which used in: - Cooling substance in air condition

sets.- propellant substance in aerosols.- flating substance in making foam

backing.- solvent substance for cleaning

electric circuits slides.

Page 18: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Methyl bromide gas: It is used as an

insecticide to preserve stored agricultural crops.

Page 19: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Halons:They are used in fire extinguishers.

Page 20: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Nitrogen oxides:They are produced from the burning fuel of ultrasound planes (Concord).

Page 21: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The effect of (CFC) compounds on Ozone layer:

CFC compounds erode ozone layer in three steps as the

following :

Page 22: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The first step:CFCl3

UVCFCl2+Cl

Page 23: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The second step:

Cl + O3 O2 + ClO

Page 24: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The third step:

ClO + O3 2O2 + Cl

Page 25: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Protecting the Ozone layer: - An international conference

was held in “CANADA" in

16-09-1987 to discuss how to protect Ozone layer and take all suitable measures

to solve this problem .

Page 26: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

-They reached a group recommendations called

“MONTEREAL PROTOCOL” where it is

signed by 191 nations :

Page 27: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

•Using of chlorofluorocarbon compounds must be reduced and find safer alternatives.

•Stop producing concord planes as their exhausts effect the Ozone layer.

Some of these recommendations:

Page 28: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

In 1990, Montreal Protocol in London has been modified in a way that all nations must ban:

• Production or handing CFC compounds otherwise they will be allowed to export their goods.

Page 29: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Amount of production In 1989 about 1010 m.t

In 1990 about 700 m.tIn 1991 about 600 m.tIn 1992 about 500 m.tIn 1993 about 400 m.tIn 1994 about 200 m.tIn 1995 less than 200 m.tIn 1996 less than 200 m.t

Page 30: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

The ministry of educationBooks

Page 31: Erosion of Ozone Layer. Erosion of Ozone layer Position of ozone layer : Ozone layer is mainly locate at height 20:40Km above sea level in the lower

Made by: Rania Ramadan A.

E-mail: [email protected]

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