On Distribution of Nitrogen in the Upper Atmosphere

Abstract

In this paper the dissociation of the nitrogen in the upper, atmosphere is studied. It is considered that the nitrogen atom is produced by dissociative recombination of the positive nitrogen ion and the electron, and by the pre-dissociation by the absorption in the Lyman-Birge-Hopfield band. The former is effective in the region above about 3.20km, while the latter predominent below that level. The disappearance of the nitrogen atom is mainly due to the recombination by two or three body collision. Approximately, the fomer mechanism of disappearance seems to be preponderant over the latter in the region where the dissociative recombination is conspicuous. Hence, two pairs of equations in an equilibrium state are solved. In the calculations, it is assumed that the temperature is constant throughout the region; the ratio of the concentation of the oxygen atom to that of the sum of the nitrogen is one-half; and the distribution of total nitrogen follows the law of gas in a static equilibrium, though the distribution of nitrogen molecule with height is not given previously. The results show that the nitrogen begins to dissociate at the level from 120km to 130km, and proceeds to completion at about 160km-220km. The concentration of the nitrogen atom has peak at about 140km-150km altitude and its magnitude is of the order of 1010/c.c..