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  2. 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 ...

  3. Atmosphere - Wikipedia

    en.wikipedia.org/wiki/Atmosphere

    The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. [2] Most organisms use oxygen for respiration ; lightning and bacteria perform nitrogen fixation which produces ammonia that is used to make nucleotides and amino acids ; plants , algae , and cyanobacteria use carbon ...

  4. Nitrogen - Wikipedia

    en.wikipedia.org/wiki/Nitrogen

    Nitrogen is the most common pure element in the earth, making up 78.1% of the volume of the atmosphere [9] (75.5% by mass), around 3.89 million gigatonnes (3.89 × 10 18 kg). Despite this, it is not very abundant in Earth's crust, making up somewhere around 19 parts per million of this, on par with niobium, gallium, and lithium.

  5. Nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_cycle

    The nitrogen cycle is an important process in the ocean as well. While the overall cycle is similar, there are different players [40] and modes of transfer for nitrogen in the ocean. Nitrogen enters the water through the precipitation, runoff, or as N 2 from the atmosphere. Nitrogen cannot be utilized by phytoplankton as N

  6. Greenhouse gas - Wikipedia

    en.wikipedia.org/wiki/Greenhouse_gas

    Greenhouse gases are infrared active, meaning that they absorb and emit infrared radiation in the same long wavelength range as what is emitted by the Earth's surface, clouds and atmosphere. [19]: 2233 99% of the Earth's dry atmosphere (excluding water vapor) is made up of nitrogen (N 2) (78%) and oxygen (O 2) (21%).

  7. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...

  8. Atmospheric chemistry - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_chemistry

    v. t. e. Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. [1] It is a multidisciplinary approach of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines.

  9. Human impact on the nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_the...

    Approximately 78% of Earth's atmosphere is N gas (N 2), which is an inert compound and biologically unavailable to most organisms.In order to be utilized in most biological processes, N 2 must be converted to reactive nitrogen (Nr), which includes inorganic reduced forms (NH 3 and NH 4 +), inorganic oxidized forms (NO, NO 2, HNO 3, N 2 O, and NO 3 −), and organic compounds (urea, amines, and ...