Nitrogen, biological cycle emission

Land/atmospheric interfacial processes which impact climate and biological activity on earth are illustrated in Figure 3. Emissions of carbon dioxide, methane, nitrogen dioxide, and chlorofluorocarbons (CFCs) have been linked to the transmission of solar radiation to the surface of the earth as well as to the transmission of terrestrial radiation to space. Should solar radiation be an internal process or an external driver of the hydrologic cycle, weather, and air surface temperatures Compounds of sulfur and nitrogen are associated with acidic precipitation and damage to vegetation, aquatic life, and physical structures. 

On a global basis, however, these estimated pollutant emissions of NO2 are probably a minor factor in the total circulation of nitrate compounds within the atmosphere. It is estimated (3) that natural emissions of NO2 may be as much as 15 times greater than the pollutant emissions or more than 700 X 10 tons. This estimate of natural emissions is based on an estimated nitrogen cycle for the atmosphere, and it is believed to result from NO produced by biological reactions. Peterson and Junge (24) recently estimated natural nitrogen compound emissions may be no more than twice as large as currently estimated pollutant sources. 

Ammonia molecules diffuse to the atmosphere (ammonia volatihzation), get transported with wind, and, finally, deposit as NH3 or NHj. Volatilized NH3 is lost for the biological nitrogen cycle at the emission location, though corrsidering larger scales it re-enters the biological N cycle after a time lag due to migration. 

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