Importance of the ozone layer and its structure
The ozone layer
The ozone layer is located at the height of 20 to 40 km above the sea level, And it is located in the lower part of the stratosphere layer, As it is the first layer of the atmospheric envelope that contains a suitable amount of oxygen gas, and it also faces the ultraviolet radiations that emitted from the Sun.
The structure of the ozone layer
The ozone layer is composed of the ozone gas which consists of three oxygen atoms.
The formation of the ozone gas
|Each oxygen atom combines with oxygen forming the ozone molecule
The oxygen molecule absorbs the ultraviolet radiation (UV), Which causes the break down of the bond between the two oxygen atoms giving two free oxygen atoms, and each oxygen atom combines with an oxygen molecule forming the ozone molecule which is composed of three oxygen atoms.
The thickness of the ozone layer
The value of the atmospheric pressure in the stratosphere layer is 0.001 of the normal atmospheric pressure at the sea level, And the temperature is less than that at the sea level. So, In these conditions, The zone gas forms a layer of a thickness of 20 km.
The English scientist “Dobson” postulated that the thickness of the ozone layer is compressed into 3 mm. Only if it is under the normal atmospheric pressure, and at the zero temperature (STP).
STP means standard temperature and normal atmospheric pressure.
So, The scientists took “Dobson” as a measuring unit of the degree of the ozone layer. The natural degree of the ozone is 300 Dobson units (100 Dobson unit (DU) is defined as 1mm thickness).