Here's why:
* Ozone Layer: The ozone layer, located in the stratosphere, plays a crucial role in absorbing most of the harmful UV radiation from the Sun. Ozone molecules efficiently absorb UV-B and UV-C wavelengths, preventing them from reaching the surface.
* Scattering: The molecules and particles in the atmosphere scatter sunlight, including UV radiation. This scattering can redirect UV rays away from the Earth's surface.
* Absorption by Other Gases: Other gases in the atmosphere, like oxygen and nitrogen, also absorb some UV radiation.
Types of UV Radiation:
* UV-A (315-400 nm): Passes through the atmosphere relatively easily and is responsible for tanning and sunburns.
* UV-B (280-315 nm): Mostly absorbed by the ozone layer, but some reaches the surface. It causes sunburns, skin cancer, and eye damage.
* UV-C (100-280 nm): Completely absorbed by the ozone layer and oxygen in the upper atmosphere. It is the most damaging type of UV radiation but does not reach the surface.
While the atmosphere protects us from most harmful UV radiation, it's important to be aware that some UV-A and a small amount of UV-B still reach the surface, requiring sun protection measures.
