ULTRAVIOLET WAVES
In the electromagnetic spectrum, ultraviolet (UV) radiation is classified as having a wavelength ranging from 400 nanometers to 10 nanometers.
There are four classifications of UV light: UVA: 400 to 315 nm, UVB: 315 to 280 nm, UVC: 280 to 100 nm, and EUV (extreme UV): 100 to 10 nm.
⌾ At the Earth’s surface, the composition of sunlight is 53% infrared, 44% visible, and 3% UV.
⌾ Of the 3% of UV that reaches the ground, approximately :
● 95% is UVA
● 5% is UVB.
● All of the EUV and most of the UVC waves are absorbed by oxygen in the upper stratosphere.
● The ozone layer then blocks most of the UVB and the remainder of the UVC not already absorbed by oxygen.
UVC light creates ozone - it disrupts the bond of oxygen molecules, forming two oxygen atoms which then quickly bond to oxygen molecules to form ozone (O3).
UVB light destroys ozone - it disrupts the bonds of ozone molecules, converting ozone back to oxygen.
The continuous interconversion of ozone and oxygen molecules converts UV radiation into thermal energy thereby filtering the most harmful range of UV light.