Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1957"

TL;DR: In this article, the authors discussed the possibility that Cerenkov radio emission by auroral particles approaching the earth may contribute to the level of the continuous component of atmospheric radio noise observed at frequencies of hundreds of kilocycles per second.

TL;DR: In this paper, a brief account of the technique is given together with a description of the method of analysing the records and results of observations over a period of one year are then given.

TL;DR: In this paper, the intensity distributions in the First Positive band system and the Meinel band systems were measured and related to theoretical data, and the altitude variations of these band systems and the strongest oxygen lines and bands were studied, the intensity ratio between the red [O I] lines λ6300/64 and the first positive bands being taken as an indication of relative altitude.

TL;DR: In this article, the effects of heavy ions are considered, and it is found that all directions of propagation are possible at audio frequencies, and that the dispersion of frequencies takes place in opposite senses for longitudinal and transverse propagation.

TL;DR: Very tentative tables are given, based on these ideas, indicating ionospheric conditions consistent with greater daytime absorption than at night, even when the nighttime bombardment is twenty times more intense than that by day as discussed by the authors.

TL;DR: The electric field and conductivity of the atmosphere were measured above thunderstorms in the central Florida area in a series of twenty-five balloon flights made at altitudes ranging from 70,000 to 90,000 ft above sea level.

TL;DR: In this article, a theory is presented which attributes the occurrence of ionospheric irregularities in the F-region to turbulent wind motion in the dynamo region at a height of 110-150 km.

TL;DR: In this article, the radio-echo observations of auroral ionization, made on a frequency of 72 Mc/s between June 1949 and October 1953, described in a previous paper of this series (Bullough and Kaiser, 1955), were compared with geomagnetic observations made at Eskdalemuir during the same period.

TL;DR: In this paper, the authors show that the observed linear dependence of the temporal parameters on distance can yield a constant height and conductivity of the equivalent homogeneous ionospheric layer independent of distance, but with different values for day and night.

TL;DR: In this paper, it was shown that point-discharge experiments may be interpreted in terms of the rapidity with which the ambient space charge is removed; this removal may be by the wind or by the ion velocity in the surrounding field, and the relative importance of the two factors will vary from experiment to experiment.

TL;DR: In this paper, the same formulation of the Simon equation is used to obtain fusion temperatures for the core of the earth's mantle from Lindemann's law by using elastic parameters determined for a given depth from seismic data.

TL;DR: In this paper, it is shown that any ionizing agent from outside the earth's atmosphere is unlikely to be responsible for the ionospheric irregularities that cause radio-star scintillations, and that the mechanism for their production must be sought in the terrestrial atmosphere.

TL;DR: In this article, an experimental investigation of the relation between the phenomena of scintillations of the radio stars and geomagnetic disturbances is described. And the results and those concerned with the reversals in drift directions are shown to be in agreement with the predictions of Martyn's theory, which ascribes the F -region phenomena to the interaction of the earth's magnetic field with an electric field communicated from the dynamo region.

TL;DR: In this paper, an equipment has been constructed to enable a long-term investigation of the temporal variations of radio star-scintillations, and a year's observations are presented in terms of the monthly average diurnal variations of scintillation which are compared with monthly average durations of spread F and geomagnetic activity.

TL;DR: The research reported in this document has been sponsored by the Electronic Research Directorate of the Air Force Cambridge Research Center, Air Research and Development Command as mentioned in this paper, and was submitted in July, 1957, to the University of Alaska in partial fulfillment of the requirements for the degree of Doctor of Philosophy.

TL;DR: In this article, absolute intensity measurements of the infra-red auroral bands are in reasonable agreement with estimates based on extrapolations from bands at shorter wavelengths, which is in line with the calculations of Heaps and Herzberg (1952).

TL;DR: Auroral radio reflections have been observed at a number of frequencies between 30 and 50 Mc/s using continuous-wave transmitters located at a distance of 860 km from the receivers as discussed by the authors.

TL;DR: In this article, a graphical construction for the prediction of waveforms, given the source conditions, indicates how the change in shape with reflection order of the ionosphere-reflected pulses can be explained in terms of source effects and the mode responses of an imperfectly conducting infinite parallel-plane wave-guide, whose known propagation characteristics give a qualitative explanation of the diversity of waveform recorded.

TL;DR: In this paper, both height and time variations of the effective recombination coefficient at night for the lower ionosphere are obtained from ionospheric data involving the use of radio waves over a wide range of frequencies.

TL;DR: In this paper, an accurate determination has been made of the barometric pressure which best measures the average air mass above this mountain, where high wind velocities are prevalent, and the existing pitot tube system for compensating for the pressure deficiency produced by the airflow over the mountain is reliable to an estimated standard deviation of ± 0.03 in.

TL;DR: In this article, the electron concentration in a layer in which there are two species of ion, with different recombination coefficients, varies during an eclipse, and the variation exhibits several features of interest.

TL;DR: In this paper, the correlation coefficients for three pairs of quantities measured experimentally at 75 and 150 kc/s frequency were found to confirm existing ideas concerning the presence of small-scale irregularities above a critical height in the lower E -region.

TL;DR: In this paper, the point-discharge current I from an isolated point at 27m and 34m height was measured and related to the wind speed W and the potential gradient F at the ground at 47 m to windward, and also to the output of an agrimeter 7 m below the point.

TL;DR: In this paper, it was shown that the reflection coefficients (ρ) measured for radio waves on 2 and 4 Mc sec −1 reflected vertically from the ionosphere do not fit the expression −log ρ = A(ƒ + ƒ L ) −2 (1) appropriate to non-deviative absorption.

TL;DR: In this paper, observations of the occurrence of the Hα line in auroral spectra obtained at Saskatoon and at Churchill are discussed with particular reference to the auroral theory of Martyn.

TL;DR: The results of some measurements of ionospheric absorption taken at Delhi during June 1954 to December 1955 are described in this paper, which shows that the diurnal variation of absorption gives ¦log ρ ¦∝ (cos χ)0.62.

TL;DR: In this paper, the authors determined the lengths of the columns of ionization formed by meteors from the available theoretical and experimental information on 1) the production and radio detection of meteoric ionization, 2) the mass distribution of shower and sporadic meteors, and 3) the distribution of sporadic meteor radiants.

TL;DR: In this article, it was shown that the echoes are produced by coherent backscatter of surface propagated waves by sea waves of length L = λ 2, and that they are not ionospheric.