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3 molecules. These ozone molecules absorb UVB light, following which ozone splits into a molecule of O 2 and an oxygen atom. The oxygen atom then joins up with an oxygen molecule to regenerate ozone. This is a continuing process that terminates when an oxygen atom recombines with an ozone molecule to make two O 2 molecules. It is worth noting ...
HFOs have an ozone depletion potential of 0.0, compared to the 1.0 of principal CFC-11, and a low GWP which make them environmentally safer alternatives to CFCs, HCFCs and HFCs. [ 63 ] [ 64 ] Hydrofluoroolefins serve as functional replacements for applications where high GWP hydrofluorocarbons were once used.
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 ...
Scientists spent years campaigning for a ban on the ozone-damaging chemical CFC-11, but 30 years after it was phased out in the 1987 Montreal Protocol, someone somewhere is breaking the rules.
During the 1970s, research indicated that man-made chlorofluorocarbons (CFCs) reduce and convert ozone molecules in the atmosphere. [4] CFCs are stable molecules composed of carbon, fluorine, and chlorine that were used prominently in products such as refrigerators. The threats associated with reduced ozone pushed the issue to the forefront of ...
The non-selective nature of the oxidation means the ozone has to be well controlled if a specific outcome is required. This can be done by maximizing exposure of the molecules, compounds, proteins, and cells to the ozone that need to be reacted with or destroyed while minimizing exposure to non-targets.
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]
The largest Antarctic ozone hole recorded (September 1985) 2012 retrospective video by NASA on the Montreal Protocol The Montreal Protocol on Substances That Deplete the Ozone Layer [2] is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.