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The gas layers of the troposphere are less dense at the geographic poles and denser at the equator, where the average height of the tropical troposphere is 13 km, approximately 7.0 km greater than the 6.0 km average height of the polar troposphere at the geographic poles; therefore, surplus heating and vertical expansion of the troposphere ...
About 90% of total ozone in the atmosphere is in the stratosphere, and 10% is in the troposphere. [5] Although ground-level ozone is less concentrated than stratospheric ozone, it is of concern because of its health effects. [6] Ozone in the troposphere is considered a greenhouse gas, and as such contribute to global warming.
Ozone in the troposhere is determined by photochemical production and destruction, dry deposition and cross-tropopause transport of ozone from the stratosphere. [2] In the Arctic troposphere, transport and photochemical reactions involving nitrogen oxides and volatile organic compounds (VOCs) as a result of human emissions also produce ozone resulting in a background mixing ratio of 30 to 50 ...
The stratosphere is the second-lowest layer of Earth's atmosphere. It lies above the troposphere and is separated from it by the tropopause. This layer extends from the top of the troposphere at roughly 12 km (7.5 mi; 39,000 ft) above Earth's surface to the stratopause at an altitude of about 50 to 55 km (31 to 34 mi; 164,000 to 180,000 ft).
As explained above, the primary cause of ozone depletion is the presence of chlorine-containing source gases (primarily CFCs and related halocarbons). In the presence of UV light, these gases dissociate, releasing chlorine atoms, which then go on to catalyze ozone destruction.
The envelope of gas surrounding the Earth changes from the ground up. Five distinct layers have been identified, the troposphere, stratosphere, mesosphere, thermosphere and exosphere.
Methane molecules react with hydroxyl radicals (OH)—the "major chemical scavenger in the troposphere" that "controls the atmospheric lifetime of most gases in the troposphere". [60] Through this CH 4 oxidation process, atmospheric methane is destroyed and water vapor and carbon dioxide are produced.
Ozone-oxygen cycle in the ozone layer. The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930. Ozone in the Earth's stratosphere is created by ultraviolet light striking ordinary oxygen molecules containing two oxygen atoms (O 2), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines ...