The ozone-rich region that absorbs much of the Sun's harmful ultraviolet…

Concept

The atmosphere is divided into layers according to how temperature changes with altitude. The ozone layer is not a separate major layer; it is the region where ozone concentration is greatest, and ozone absorbs much of the Sun's harmful ultraviolet radiation.

Most atmospheric ozone is concentrated about 15–35 km above Earth, within the stratosphere.

Application

1. Locate the protective ozone concentration at roughly 15–35 km above the surface.

2. The troposphere reaches only to the tropopause, generally about 8–15 km, so the 15–35 km band lies mainly above it.

3. The stratosphere begins above the tropopause and extends to about 50 km, so the ozone-rich band lies inside this layer.

Contrast

• Troposphere: the lowest layer, where most clouds and weather occur.

• Mesosphere: the higher layer beginning near 50 km, above the main ozone-rich band.

• Ionosphere: an ionized region important for radio propagation; it is not one of the temperature-defined layers that contains the ozone maximum.

Cross-check

NASA places the ozone layer in the stratosphere and describes it as lying about 15–40 km above Earth; this independently agrees with the atmospheric-layer boundaries used above.

Result

The ozone layer is situated in the stratosphere.