Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1974"

TL;DR: In this paper, the penetration, diffusion and slowing down of electrons in a semi-infinite air medium has been studied by the Monte Carlo method and the results are applicable to the atmosphere at altitudes up to 300 km.

TL;DR: In this paper, the relationship between quasi-periodic VLF emissions and geomagnetic pulsations was examined based on observations at Syowa Station, Antarctica, where the spectral form depends significantly on the modulation period.

TL;DR: In this article, a semi-empirical effort is made to construct profiles of electron density, positive ion density and positive and negative ion composition for mid-latitude summer daytime for moderate solar activity period.

TL;DR: In this article, several ionospheric irregularity models with different power spectra are compared with the observed results and both magnitude and frequency dependence of the scintillation index are investigated.

TL;DR: In this article, the authors show that positive streamers propagate within a uniform field region having an applied electric field greater than the minimum value needed to cause streamers to bridge the interelectrode gap.

TL;DR: In this article, the ducted and partly ducted propagation of artificial VLF waves through the magnetosphere has been studied by means of data from the FR-1 satellite experiment, in which fixed-frequency (16.8 kHz) waves radiated by a transmitter on the ground (at L = 2.1) are received by the satellite at 750 km altitude both in the zone close to the transmitter and in the conjugate zone.

TL;DR: In this article, a single sferics receiver located at the McGill Radar Weather Observatory has located individual lightning flashes in azimuth and time, at ranges 8-200 km, and the flashes were close in time and space to precipitation cores or maxima, specifically to cores for which the radar target intensity level in excess of 43 dBZ extended upward through height 7 km.

TL;DR: In this paper, a statistical analysis of the results of Incoherent Scatter measurements over 3 years leads to characterize a dominant semi-diurnal oscillation, S 2 4, which can be excited at lower heights, but it becomes dominant only if the other modes, particularly S 2 2, are filtered out under 100 km.

TL;DR: The diffraction theory of interplanetary scintillations, which allows a connection to be established between the spatial spectrum of electron-density fluctuations in the irregular medium and the power spectrum of intensity scintillation observed on the ground, is reviewed and applied to the case of the ionosphere.

TL;DR: In this paper, a VHF backscattering experiment using the Jicamarca incoherent-scatter radar is described for a mesospheric height, where the echo power during the day varies intermittently and sporadically over a range of almost 30 dB with a median strength about 4 dB above the incoherentscatter level.

TL;DR: In this paper, the observed amplitude of ULF turbulence is sufficient to induce parasitic pitch-angle scattering of relativistic electrons at the strong diffusion limit, which is consistent with unstable cyclotron resonant generation which occurs most favourably at plasma densities higher than normally existant outside the plasmapause.

TL;DR: In this article, the authors examined the rate of compression at mid-latitudes for three different assumptions about the ion motion at ionospheric heights, and showed that the geomagnetic field is virtually incompressible.

TL;DR: In this article, a multistatic CW incoherent scatter radar system is described, and its use for measuring F2-region plasma drifts in the magnetic meridian plane is explained.

TL;DR: The theory and practice of four ground-based radio wave methods of sounding the Earth's ionosphere that came into being since the Second World War is reviewed in this paper. But, the authors do not discuss the performance of these methods.

TL;DR: In this paper, the negative effects on the daily variation of H occur primarily in the morning hours around 07 hr and in the evening between 15 and 17 hr, which correspond to that of maximum negative effect in H due to the lunar tidal wave.

TL;DR: In this paper, it was suggested that the observed phenomena cannot be explained on the basis of the present theory of planetary waves and therefore, coupling is effected by a modulation-demodulation process involving short-period internal atmospheric gravity waves propagating obliquely to meteor heights.

TL;DR: In this paper, an interpretive procedure for high-resolution ionospheric radio echo phase measurements at spaced antennas and spaced radio frequencies is described and applied, and a procedure is given for calculating the direction of arrival and group-path simultaneously (i.e., the grouppath vector).

TL;DR: In this paper, an approximate calculation shows how hydromagnetic waves transmitted across the meridian can be enhanced in a selected period range by a plasmasphere resonance which combines transverse and compressional modes.

TL;DR: In this paper, the influence of the solar plasma on geomagnetic and atmospheric phenomena is considered and the effect of the magnetic field on the magnetically conjugate points relative to the direction of the interplanetary magnetic field is investigated.

TL;DR: In this article, the eigenvalues or equivalent depths of Laplace's tidal equations are calculated for complex frequencies, where the real terms of the complex frequencies are the angular frequencies of the waves; the imaginary terms arise from the assumption of a neutral ion drag responsible for a significant dissipation mechanism of horizontal wave motions at thermospheric heights.

TL;DR: In this article, the authors compared the received daytime phase of long distance, cesium-controlled, VLF transmissions with the height variations of the 10 mb isobaric surface during the first 3 months of 1965 and 1969.

TL;DR: Incoherent scatter observations at the Arecibo Observatory have shown that nighttime electron density enhancements are formed in the upper E-region and move down to merge with a stable Es-layer lying between 105 to 110 km.

TL;DR: In this article, a theoretical study of the Dst component of magnetic storms is presented, and the dynamic characteristics are found significantly different for Joule dissipation and electron precipitation, leading to the conclusion that the former is probably the predominant heat source for the upper thermosphere.

TL;DR: In this paper, the field-aligned current induced by asymmetric dynamo action in the northern and southern hemispheres is calculated, on the basis of some realistic models of the distribution of ionospheric wind and conductivity.

TL;DR: In this article, the daily behavior of the mid-latitude thermosphere is studied by incoherent scatter radar at Millstone Hill, Massachusetts (42.6°N, 71.5°W).

TL;DR: In this article, neutral air velocities at F2-layer heights, electric fields and hmF2 were measured for eight nights by the Arecibo radar for 8 nights by a computer program which solved the continuity equation for the F-region.

TL;DR: The ion processes subsequent to the initial production of metal atomic ions and electrons in meteor trains are examined in this article, where the set of diffusion equations describing the behaviour of the various ion species is solved numerically yielding the concentrations of ions expected to be present in an expanding meteor train.

TL;DR: In this paper, neutral air motions have been deduced from the triangulation of the neutral component of barium point cloud releases carried out in the altitude range between 140 and 260 km in low and high geomagnetic latitudes.

TL;DR: In this article, a general method of computing ground level magnetic effects due to large-scale three-dimensional current systems external to the Earth's surface is developed, particularly suitable for field-aligned magnetospheric currents which have their source in the ionospheric dynamo region.