where is an ozone shield seen?

Answer 1

It is mainly located in the lower portion of the stratosphere from approximately 15 km to 35 km above Earth's surface, though the thickness varies seasonally and geographically.

The ozone layer is the part of the Earth's atmosphere which contains relatively high concentrations of ozone . "Relatively high" means a few parts per million—much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere.

Although the concentration of ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation emitted from the Sun.Depletion of the ozone layer allows more of the UV radiation, and particularly the more harmful wavelengths, to reach the surface, causing increased genetic damage to living organisms.

Answer 2

Our global footprint can be seen in the destruction of the ozone layer, which has become thinner in places, and has actual holes in the Antarctic region. The hole in the ozone layer above Antarctica is thought to be as big as the USA and as deep as Mount Everest! Over Europe the ozone layer is thinning as well. Perhaps as much as 10% of the ozone shield has been destroyed. (Source: Dirty Planet – Friends of the Earth, Caroline Clayton, 2001)