ozone layer

American  

[oh-zohn ley-er] / ˈoʊ zoʊn ˈleɪ ər /

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).

---

ozone layer British  

noun

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

---

ozone layer Scientific  

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.

2. Also called ozonosphere

3. See Note at ozone

---

ozone layer Cultural  

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

---

Discover More

The ozone layer absorbs harmful ultraviolet radiation from the sun and is thus very important to the health of human beings and other life forms on Earth. The Earth's ozone layer could be at risk because of the action of chlorofluorocarbons, but international treaties have banned the production of these chemicals. The ozone layer is expected to return to normal in a few decades. (See ozone hole.)

Example Sentences

HFCs were introduced in the 1990s to replace chemicals that had been found to erode the ozone layer, but turned out to be catastrophic for global warming.

From Barron's • May 21, 2026

Halley VI is focused on space and atmospheric data, as well as studying the Brunt Ice Shelf on which it's located close to the coast, and the hole in the Earth's ozone layer.

From BBC • Feb. 22, 2026

"Our largest concern is aluminium and aluminium oxides interacting with the ozone layer," Wing says.

From BBC • Feb. 19, 2026

American leadership in science, technology, and policy has been central to identifying these risks and driving actions that protect the ozone layer as well as the health and prosperity of the American people.

From Science Daily • Dec. 4, 2025

In addition to war and crime and cruelty, we have to worry about environmental problems—about pollution, the growing hole in the ozone layer, the greenhouse effect, and global warming.

From "My Life with the Chimpanzees" by Jane Goodall