Question

Why is ozone layer called ozone umbrella/shield?

Answer 1

Ozone layer is called ozone umbrella/shield because it filters harmful, high-energy ultraviolet rays that come from the Sun to the Earth. UV rays split the ozone into molecular and atomic oxygen, thereby liberating the heat that warms the stratosphere. In this way, ozone layer protects the Earth.

O₃ $\stackrel{UV}{\to }$ O₂ + [O] + Heat
Ozone Molecular Atomic
oxygen oxygen