Lightning, nitrogen fixation

Two pathways for nitrogen fixation, a source of nitrogen for plants, (a) Both free-living bacteria in the soil and microorganisms in root nodules produce ammonium ions, (b) Lightning provides the energy needed to form nitrate ions from atmospheric nitrogen. 

The highly endothermic nitric oxide can be synthesized from the elements dinitrogen and dioxygen in an electric arc (AEf = 180.6kJmol ). This also takes place in the natural nitrogen fixation by lightning. 

Barucki W. and Chameides W.L., The global nitrogen fixation of lightning, submitted. Rev. Geophys. and Space Phys. (1983). 

Natural processes Biological nitrogen fixation Lightning All natural processes 1950 100-200 5 105-205 2000 100-200 5 105-205... 

Navarro-Gonzalez R., McKay C. P., andMvondo D. N. (2001) A possible nitrogen crisis for Archaean life due to reduced nitrogen fixation by lightning. Nature 412, 61 -64. 

Two primary routes for nitrogen fixation exist in nature. In the atmosphere, lightning combines N2 and O2 to form NO. 

Nitrogen fixation Nitrogen can be fixed for plants in three ways by lightning, by nitrogen-fixing bacteria living in the roots of plants or in the sod, and by commercial synthesis reactions such as the Haber ammonia process. 

Noxon, J. F, 1976 Atmospheric nitrogen fixation by lightning. Geophys. Res. lett. 3, 463-465. Ohta, S. and Ito, T., 1974 Method of measurement of very low concentrations of submicron aerosols. WMO Special Environmental Rep. 3, 387-393. 

Table 12-8 also lists residence times of nitrogen in the atmosphere that one calculates from the individual fluxes. Biological nitrogen fixation results in a residence time of 18 million yr, which is much shorter than the age of Earth and its atmosphere. Even the oxidation of N2 in lightning discharge leads to a residence time that is shorter. Lewis and Randall (1923) and Sillen (1966) pointed out that in the presence of free oxygen and liquid... 

Doyle, G. J. (1961). Self-nucleation in the sulfuric acid water system. J. Chem. Phys. 35,795-799. Drapcho, D. L., D. Sisterson, and R. Kumar (1983). Nitrogen fixation by lightning activity in a thunderstorm. Atmos. Environ. 17, 729-734. 

---