Measurement of the Nitric Oxide Altitude Distribution in the Mid-Latitude Mesosphere

A simple rocket-borne system has been developed for deriving nitric oxide concentration in the mesosphere from measurements of resonantly scattered solar ultraviolet radiation in the NOg ammbaa nd near 2150 •. The NO signal is extracted from a background of Rayleigh-scattered light by a direct measurement of this scattered light by use of an NO absorption cell. This system was utilized to measure the NO concentration above White Sands, New Mexico, in the altitude range from 69 to 101 km. The derived NO profile shows a concentration of about 3 x 10 7 cm-3 at 67 and 100 km with a deep valley (more than an order of magnitude less) at about 84 km. Comparison with model calculations indicates that the time constant for NO chemistry is smaller than or comparable with that for transpor

Hβ Emission during Auroral Breakup

The behaviour of H_β emission is examined at the onset and in the course of auroral breakup, on the basis of meridian scanning data of photometers for H_β and green line along with all-sky photographs obtained at Syowa Station, Antarctica in 1971. The result shows that an auroral breakup starts at the poleward boundary of the pre-existing hydrogen arc, that a global breakup frequently starts when an electron auroral arc comes into contact with the pre-existing hydrogen arc, that the enhancement of H_β takes place in the region bounded by the westward travelling surge, the poleward shifting arc and the pre-existing hydrogen arc with a spatial negative correlation between electron aurora and hydrogen emission, and that the behaviour of a local breakup is substantially similar to that of a global breakup though it has no "contact" of electron aurora

Auroral UV and X-Ray Emission in Antarctica

The ultraviolet and X-ray features of the polar aurora were studied by means of the sounding rockets which were launched from Syowa Station, Antarctica in 1971. The distribution of energetic electrons was obtained from the data of the X-ray counters. The photometric data of the ultraviolet ionization chambers revealed a dual structure of the optical excitation in the active aurora