Friday, 11 October 2013

Ozone layer and ozone depletion

                            Here we will study about ozone layer and ozone depletion. Ozone layer is very beneficial for human being. On the other hand, ozone depletion is harmfull for all plant, animal and human.
Ozona layer and ozone depletion;
                                                            Ozone layer is a layer which is present between stratosphere and distance from Earth is about 25-30 km. Ozone layer is made of ozone gas (O3). Ozone gas is made when molecule oxygen and atomic oxygen react ;
                                                                                         O +  O ─────> O3 (ozone gas)
Ozone layer is very tough layer it can not pass UV (ultraviolet) radiation of sun. Just few waves which is very strong pass through it. In above figure we can see the ozone layer light blue color just above Earth.
Know we study about ozone depletion a major problem for all human being. The chloroflurocarbons (ClFCs) which is used in air conditioner and a refrigerator is a major cause of ozone depletion. When Chloroflurocarbons go upward and reach at ozone layer the ultraviolet radiation of sun break them and CFCl3 and Chlorine radical is form.
                                                                   CFCl4  +  UV ─────> CFCl3  +  Cl(radical)
This radical is very reactive and they react with ozone gas (O3) to form oxygen.
                                                                   CFCl+  UV ─────> CFCl+  Cl
                                                                     O3  +   Cl   ─────> O2   +  OCl
                                                                            OCl    ─────> O  +  Cl
                                                                          O + O  ─────> O2
In above, we will discuss first cause of ozone depletion the second cause of ozone depletion is below ;                               In second cause, TV and FM radio waves is involve which effect on F and E layer of ionosphere and then ozone deplete. Now we read in explain. In case of F layer, F layer have two region F1 and F2. F1 contain NO ion and F1 is effected by radio waves. When radio wave pass through F1 layer O positive and N negative ion produced. O positive ion flow toward sun and N negative ion react with ozone O3 to form oxygen:
                                                                                                    N  + O3 ─────> NO + O2
NO ion again react with O2 to become NO2:
                                                                             NO + O2 ─────> NO2 + O(radical)

In this way, ozone layer break and ozone deplete. The region of ozone which deplete is known as ozone hole.In 1980 the ozone hole is found in Antarctica and in 1990 ozone hole again found in arctic ocean.      

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