Accession Number : AD0658450

Title :   D-REGION PROCESSES IN NON-POLAR LATITUDES,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK IONOSPHERE RESEARCH LAB

Personal Author(s) : Mitra,A. P.

Report Date : 15 JUN 1967

Pagination or Media Count : 101

Abstract : The report presents the results of a reexamination of three major areas of D region aeronomy, namely: the height distribution of nitric oxide, the distribution of the effective recombination coefficient and the nature and distribution of negative ions. For nitric oxide, a previous estimate by the author from the solar cycle variation in the D region electron density is supplemented by some new estimates from: observed diurnal variation of the electron density and from recent measurements of ion composition. These, and a few other ionospheric estimates currently available, as also considerations of the photochemistry of nitric oxide, indicate that a distribution consistent with most of these estimates is of the form n(NO) = 0.4 exp(-3700/T)n(O2) + 5 x 10 to the minus 7th power n(O). Values of the effective day time loss rate Psi have been obtained from simultaneous use of information on the ionizing radiation and several electron density profiles derived with rocket and ground-based experiments. Examination of these, as also the host of determinations on the effective recombination coefficient alpha' that have in the past been made from the variations in electron density or absorption with the time of the day or during eclipses and solar flares, indicate that: (i) alpha' has a value around 2 x 10 to the minus 7th power cu cm near 100 Km, (ii) the dissociative recombination coefficient for NO(+) is about the same as that for O(+2) (both being around 2 x 10 to the minus 7th power cu cm), and (iii) negative ions are not important above 70 Km during day and above 85 Km during night. The observational results appear to agree with an empirical relationship of the form. (Author)

Descriptors :   (*IONOSPHERE, RECOMBINATION REACTIONS), IONS, DIURNAL VARIATIONS, ELECTRON DENSITY, SOLAR ECLIPSES, IONOSPHERIC DISTURBANCES, NITROGEN OXIDES, THEORY, MEASUREMENT, ELECTRONS

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE