Gravenhorst, G.FZJ* ; Ehhalt, D. H.FZJ* ; Böttger, A.FZJ*

1978
Kernforschungsanlage Jülich, Zentralbibliothek, Verlag Jülich

Report No.: Juel-1558

Abstract: The atmospheric cycles of nitrogenous trace compounds for the Northern and Southern Hemisphere are discussed . Source strengths and destruction rates for the nitrogen oxides: NO, NO$_{2}$ and HNO$_{3}$ (NO$_{x}$), and ammonia (NH$_{3}$) are given as a function of latitude over continents and oceans. The global amounts of NO$_{x}$-N and NH$_{3}$-N produced annually in the period 1950-1975 (34 $\pm$ 5 x 10$^{12}$ g NO$_{x}$-N/yr and 29 $\pm$ 6 x 10$^{12}$ g NH$_{3}$-N/yr) are much less than previously assumed . Globally, natural and anthropogenic emissions are of similar magnitude. The NO$_{x}$ emission from anthropogenic sources is 1.5 times that from natural processes in the Northern Hemisphere whereas in the Southern Hemisphere it is a factor of 3 or 4 less. More than 80% of atmospheric ammonia seems to be derived from excrements of domestic animals, mainly cattle. Atmospheric NO$_{x}$ and NH$_{3}$ are removed from the atmosphere mostly by bulk deposition : 24 $\pm$ 9 x 10$^{12}$ g N0$^{-}_{3}$-N/yr and 21 $\pm$ 9 x 10$^{12}$ g NH$^{+}_{4}$-N/yr. Another fraction may be removed by absorption on vegetation and bare soils and, in the case of ammonia, by oxidation within the atmosphere.

1. Troposphäre (ICG-2)