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  2. Useful conversions and formulas for air dispersion modeling

    en.wikipedia.org/wiki/Useful_conversions_and...

    Pollution regulations in the United States typically reference their pollutant limits to an ambient temperature of 20 to 25 °C as noted above. In most other nations, the reference ambient temperature for pollutant limits may be 0 °C or other values. 1 percent by volume = 10,000 ppmv (i.e., parts per million by volume).

  3. International Standard Atmosphere - Wikipedia

    en.wikipedia.org/wiki/International_Standard...

    at each geopotential altitude, where g is the standard acceleration of gravity, and R specific is the specific gas constant for dry air (287.0528J⋅kg −1 ⋅K −1). The solution is given by the barometric formula. Air density must be calculated in order to solve for the pressure, and is used in calculating dynamic pressure for moving vehicles.

  4. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    1 atm = absolute pressure of 101.325 kPa or 1.01325 bar; mol = gram mole and kmol = 1000 gram moles; Pollution regulations in the United States typically reference their pollutant limits to an ambient temperature of 20 to 25 °C as noted above. In most other nations, the reference ambient temperature for pollutant limits may be 0 °C or other ...

  5. U.S. Standard Atmosphere - Wikipedia

    en.wikipedia.org/wiki/U.S._Standard_Atmosphere

    The U.S. Standard Atmosphere is a static atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations. The model, based on an existing international standard, was first published in 1958 by the U.S. Committee on Extension to the Standard Atmosphere, and ...

  6. Barometric formula - Wikipedia

    en.wikipedia.org/wiki/Barometric_formula

    Pressure as a function of the height above the sea level. There are two equations for computing pressure as a function of height. The first equation is applicable to the atmospheric layers in which the temperature is assumed to vary with altitude at a non null lapse rate of : = [,, ()] ′, The second equation is applicable to the atmospheric layers in which the temperature is assumed not to ...

  7. Atmospheric dispersion modeling - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_dispersion...

    The technical literature on air pollution dispersion is quite extensive and dates back to the 1930s and earlier. One of the early air pollutant plume dispersion equations was derived by Bosanquet and Pearson. [2] Their equation did not assume Gaussian distribution nor did it include the effect of ground reflection of the pollutant plume.

  8. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    National Ambient Air Quality Standards. US counties that are designated "nonattainment" for the Clean Air Act's NAAQS, as of September 30, 2017. The U.S. National Ambient Air Quality Standards (NAAQS, pronounced / ˈnæks / naks) are limits on atmospheric concentration of six pollutants that cause smog, acid rain, and other health hazards. [1]

  9. Outline of air pollution dispersion - Wikipedia

    en.wikipedia.org/wiki/Outline_of_air_pollution...

    The following outline is provided as an overview of and topical guide to air pollution dispersion: In environmental science, air pollution dispersion is the distribution of air pollution into the atmosphere. Air pollution is the introduction of particulates, biological molecules, or other harmful materials into Earth's atmosphere, causing ...