A temperature-dependent model of the thermospheric odd nitrogen.

Abstract

The diurnal variations of odd nitrogen species (N, NO) in the thermosphere are modelled by solving the time-dependent, one-dimensional continuity equations with the diffusion transport which have been developed by OGAWA and SHIMAZAKI (1975). By comparing the calculated results with N and NO distributions which were determined in an airglow (NI 5, and mass spectrometric observations the following conclusions have emerged.(1) The quantum yield of N(2D) in the reactions energetically capable of producing the excited species should be larger than 0.5, and probably as large as 0.9. (2) The quenching of N(2D) by atomic oxygen is important at altitudes above 120km. In order to be consistent with the observation of NI 5,200A airglow, the quenching coefficient must be as large as 1X10-12cm3s-1. (3) The variability of NO density profiles obtained by various experimenters is largely interpreted to be due to the large diurnal variations of odd nitrogen expected from a large diurnal change in the thermospheric temperature which is also under the control of solar activities.

Diurnal and seasonal effects in E region low‐latitude nitric oxide

“…The rate of dissociation of N•. needed to balance the mutual destruction of NO and N during the day is about 4 x 103 cm-3 s-i; this rate is in good accord with published models (see, for example, Strobel et al [ 1976] and Kondo and Ogawa [ 1977]).…”

“…In Kondo and Ogawa [ 1977], both using values of -•1 X 10 -•' cm 3 s -•) show a much larger variation, up to a factor of 3. Since the models also differ in their assumption about the relative production rates of NOS) and N(•'D) and since they refer to mid-latitudes rather than to the equator, direct comparisons of our data to the models are not likely to be productive.…”

On a generalization of stable distributions

“…The NO number density obtained by Roble et a1 (1978) is much smaller (one order of magnitude) than that of the other two models below 110 km, and has an intermediate distribution in the upper E-region. On the other hand, the present calculations show a height distribution of n ( N 0 ) similar to the one obtained by Kondo and Ogawa (1977) in the region above 110 km, although the former values are greater. They are approximately constant below that height.…”

“…Figures 4((0 and 4(b) show the calculated distribution of n(NO) (curves C). Figure 4(a) also contains the results of the previously mentioned ionospheric models (curves A and B) together with the theoretical results of Kondo and Ogawa (1977) who studied the chemistry of the odd nitrogens (curve D). It should be noted that the results of Kondo and Ogawa (1977) and those of Chakrabarty eta/( 1978) coincide at lower heights, while above 110 km the difference in the NO concentration between the two models is up to one order of magnitude.…”

“…Figure 4(a) also contains the results of the previously mentioned ionospheric models (curves A and B) together with the theoretical results of Kondo and Ogawa (1977) who studied the chemistry of the odd nitrogens (curve D). It should be noted that the results of Kondo and Ogawa (1977) and those of Chakrabarty eta/( 1978) coincide at lower heights, while above 110 km the difference in the NO concentration between the two models is up to one order of magnitude. The NO number density obtained by Roble et a1 (1978) is much smaller (one order of magnitude) than that of the other two models below 110 km, and has an intermediate distribution in the upper E-region.…”