Nitrogen anthropogenic perturbations

ANTHROPOGENIC PERTURBATIONS OF THE MARINE NITROGEN AND PHOSPHORUS CYCLES... 

Table 12-4 Summary of anthropogenic perturbation to the nitrogen cycle...

The model-calculated partitioning of the human-induced perturbation fluxes In the global coastal margin of (a) nitrogen and (b) phosphorus for the period from 1850 to the present (2000) and projected to 2035 under the business-as-usual scenario, In units of lO mol/y and Mtons/y. The anthropogenic sources are plotted on the (-) side and the resulting accumulations and enhanced export fluxes are plotted on the +) side. Source-. From Mackenzie, F. T, et al. (2002). Chemical Geology 190, 13-32. 

As the influence of human activities to the atmosphere is enhanced, the atmospheric concentrations of anthropogenic species such as nitrogen oxides (NOx = NO +NO2), volatile organic compounds (VOCs), etc. increase over a certain level. Tropospheric chemistry then exceeds the range of perturbation to the natural atmosphere, a chemical reaction system characteristic to the polluted atmosphere, sometimes called smog reactions, is brought about. Oxidation reaction mechanisms for the NOx-VOC mixtures directly related to the OH chain reaction are described in this section. 

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