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  2. NOx - Wikipedia

    en.wikipedia.org/wiki/NOx

    In atmospheric chemistry, NOx is shorthand for nitric oxide (NO) and nitrogen dioxide (NO2), the nitrogen oxides that are most relevant for air pollution. [1][2] These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone. NOx gases are usually produced from the reaction between nitrogen and oxygen ...

  3. Ground-level ozone - Wikipedia

    en.wikipedia.org/wiki/Ground-level_ozone

    Ground-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. [1][2] Ozone is also an important constituent of the ...

  4. Ozone - Wikipedia

    en.wikipedia.org/wiki/Ozone

    Ozone (/ ˈoʊzoʊn /) (or trioxygen) is an inorganic molecule with the chemical formula O. 3. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O. 2, breaking down in the lower atmosphere to O.

  5. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    The atmosphere has a mass of about 5.15 × 10 18 kg, [3] three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km (62 mi) or 1.57% of Earth's radius, is often used as ...

  6. Ozone depletion - Wikipedia

    en.wikipedia.org/wiki/Ozone_depletion

    Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, [citation needed] and a much larger springtime decrease in stratospheric ozone (the ozone layer) around Earth's polar regions. [1] The latter phenomenon is referred to as the ...

  7. Nitrous oxide - Wikipedia

    en.wikipedia.org/wiki/Nitrous_oxide

    2 O entering the atmosphere is the result of human activity, [116] control of nitrous oxide is part of efforts to curb greenhouse gas emissions. [ 130 ] Most human caused nitrous oxide released into the atmosphere is a greenhouse gas emission from agriculture , when farmers add nitrogen-based fertilizers onto the fields, and through the ...

  8. Air pollution - Wikipedia

    en.wikipedia.org/wiki/Air_pollution

    Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. [1] It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological agents ...

  9. Nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_cycle

    The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation ...