ozone layer

noun

1. Meteorology. the layer of the upper atmosphere where most atmospheric ozone is concentrated, from about 8 to 30 miles (12 to 48 km) above the earth, with the maximum ozone concentration occurring at an altitude of about 12 miles (19 km).

noun

1. the region of the stratosphere with the highest concentration of ozone molecules, which by absorbing high-energy solar ultraviolet radiation protects organisms on earthAlso called: ozonosphere

1. A region of the atmosphere, lying mostly in the stratosphere, containing relatively high levels of ozone, with the greatest concentrations occurring from about 15 to 30 km (10 to 19 mi) above the Earth’s surface. The ozone absorbs large amounts of solar ultraviolet radiation, preventing it from reaching the Earth’s surface. The concentration of ozone in the ozone layer is usually under 10 parts per million. Also called ozonosphere See Note at ozone.

A band of ozone in the upper atmosphere. Ozone is a molecule made of three atoms of oxygen instead of the usual two.