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  2. Ozone layer - Wikipedia

    en.wikipedia.org/wiki/Ozone_layer

    Ozone-oxygen cycle in the ozone layer. The Earth's ozone layer formed about 500 million years ago, when the neoproterozoic oxygenation event brought the fraction of oxygen in the atmosphere to about 20%. [7] The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930.

  3. Ozone - Wikipedia

    en.wikipedia.org/wiki/Ozone

    Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth's atmosphere. It is present in very low concentrations throughout the atmosphere, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation.

  4. Ground-level ozone - Wikipedia

    en.wikipedia.org/wiki/Ground-level_ozone

    [1] [2] Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface. [3] The troposphere extends from the ground up to a variable height of approximately 14 kilometers above sea level.

  5. Hole in the Earth's ozone layer Is finally closing up, NASA says

    www.aol.com/article/2015/05/15/hole-in-the...

    The Weather Channel A hole in our atmosphere more than twice the size of the United States is finally beginning to close up, and might even be completely gone by the end of the century, according ...

  6. Ozone–oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Ozone–oxygen_cycle

    Most of the ozone production occurs in the tropical upper stratosphere and mesosphere. The total mass of ozone produced per day over the globe is about 400 million metric tons. The global mass of ozone is relatively constant at about 3 billion metric tons, meaning the Sun produces about 12% of the ozone layer each day. [1]

  7. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    Stage 3 (1.85–0.85 Ga): O 2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer. Stages 4 and 5 (0.85 Ga–present): O 2 sinks filled, the gas accumulates. [1]

  8. Photodissociation - Wikipedia

    en.wikipedia.org/wiki/Photodissociation

    The formation of the ozone layer is also caused by photodissociation. Ozone in the Earth's stratosphere is created by ultraviolet light striking oxygen molecules containing two oxygen atoms (O 2), splitting them into individual oxygen atoms (atomic oxygen). The atomic oxygen then combines with unbroken O 2 to create ozone, O 3. [17]

  9. UN says ozone layer slowly healing, hole to mend by 2066

    www.aol.com/news/un-says-ozone-layer-slowly...

    Earth’s protective ozone layer is slowly but noticeably healing at a pace that would fully mend the hole over Antarctica in about 43 years, a new United Nations report says. A once-every-four ...