Question

Earth receives a lot of ultra violet radiation from the sun. Most of it doesn't reach the ground because it is?

1) Absorbed by the ozone layer
2) Reflected by the atmosphere
3) Scattered by the clouds
4) Blocked by the Earth's magnetic field

Answer 1

The ultra violet radiation from the sun is mostly absorbed by the ozone layer, particularly the more harmful UV-B and UV-C types, making the ozone layer a crucial protective shield for life on Earth.

Step-by-step explanation:

Earth receives a significant amount of ultra violet radiation from the sun, which is harmful to living organisms. The radiation that reaches our planet is primarily in three forms: UV-A, UV-B, and UV-C. The majority of this harmful radiation does not reach the ground because it is absorbed by the ozone layer. This layer is located in the stratosphere, 10 to 50 kilometers above the Earth, and it plays a crucial role in protecting life.

The ozone layer efficiently absorbs the higher-energy UV-B (290-320 nm) and UV-C (220-290 nm) radiations. UV-B has been associated with various detrimental effects, including an increase in skin cancers, cataracts, and damage to crops and marine organisms.

Thus, stratospheric ozone acts as a protective shield, allowing only UV-A, which has less energy, to reach the Earth's surface. In fact, 99% of the sunlight that reaches us is in the form of UV-A radiation, due to the ozone layer's filtering effect.