Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1980"

TL;DR: A fast and efficient method for analysing ionospheric drift records employing the concepts of full correlation analysis ( Briggs et al., 1950) is described in this paper, where only the most accurately determined experimental data, viz. the width of the mean auto correlogram, and the positions and magnitudes of the maxima in the cross correlograms are required.

TL;DR: In this article, various radar techniques which can be used to observe wind velocities and turbulence in the troposphere, stratosphere and mesosphere are discussed and the relative advantages and disadvantages of the two techniques are discussed for situations where both are practicable.

TL;DR: In this paper, the authors make use of multifrequency, phase-coherent radio signals transmitted through the ionosphere to obtain a bivariate representation of complex-signal statistics and then form conclusions based on chi-square tests of four hypotheses against histograms of intensity and phase.

TL;DR: In this article, the authors identify global zones of energetic particle precipitation in the nighttime atmosphere during disturbed magnetic conditions in rocket, satellite, and ground-based measurements and identify distinct low and mid-latitude zones; poleward from the plasmapause the precipitation flux is nearly isotropic and variable, and it consists of electrons and ions with the maximum intensity of the proton auroral zone occurring about 5 deg equatorward of the maximum of the electron auroral zones.

TL;DR: In this paper, simultaneous observations at UHF (257 MHz) from three stations in the equatorial region (Huancayo, Peru, Natal, Brazil and Accra, Ghana) were made between Jan. 1977 and Jan. 1978.

TL;DR: In this paper, two-dimensional eddy diffusion around mesopause heights is modelled by means of a set of parameters relating eddy transports to average fields of meteorological quantities like wind variance and potential temperature.

TL;DR: In this article, the influence of turbulent mixing, vertical motions and atmospheric tides on the densities of N2, O and O2 in the lower thermosphere is investigated for a one-dimensional time-dependent diffusive-photochemical model.

TL;DR: In this article, the frequency type of spread-F seems to be associated with the post sunset uplifting of the F-layer which itself is caused by the strong eastward horizontal electric field in the evening before its reversal to the normal nighttime westward direction.

TL;DR: In this paper, a theory of radio windows is given that uses a full wave integration of the governing differential equations in order to deal with the large gradient of electron concentration in a cold plasma.

TL;DR: The history and present state of research on whistlers are reviewed in this paper, where a review of the current state of the art on whistler-mode wave-particle interactions is presented.

TL;DR: The results of an experimental investigation of the dynamics of medium-scale travelling ionospheric disturbances (TID) are presented and the properties of TID behaviour in the F-region and their connection with thermospheric winds, are considered as discussed by the authors.

TL;DR: In this paper, it was shown that the electron density profiles of sporadic-E layers can be interpreted as an effect of unstable wind shears and that the maximum value of the shear is about 50 m/s/km which corresponds to a Richardson number of 1/4.

TL;DR: In this article, a simplified D -region ion chemistry scheme is combined with plausible models for the electron temperature dependence of electron attachment and ion-electron recombination processes in order to study plasma density modifications induced by continuous high power radio wave heating.

TL;DR: In this paper, the horizontal phase trace velocity lies between 300 and 1000ms−1 with periods in the range 50 to 150 min and there is evidence that the derived velocity generally increases with increase of wave period.

TL;DR: In this paper, the authors examined the correspondence between electron and ion pulsations, and the velocity dispersion in electrons and ions was evaluated, and devised a method for identifying positive ions using a velocity spectrogram, though the results in this instance are inconclusive.

TL;DR: By comparing recordings made at Pamatai, Tahiti, with those from the magnetometer array operated by the Institute of Geological Sciences, it was observed that Pi's occur at low latitudes on the dayside of the Earth coincidentally with Pi2's recorded (and thought to be generated) near the local midnight sector as mentioned in this paper.

TL;DR: In this paper, the authors investigated the magnitude of the systematic error in the azimuthal bearing due to multipath propagation and incident wave polarisation for different ionospheric and ground parameters for these three different systematic error types.

TL;DR: In this article, it is shown that the wave normal direction of upgoing whistler-mode waves can become field-aligned at and above the altitude of the refractive index minimum and this can lead to trapping of waves through the side of a suitably positioned duct.

TL;DR: In this article, wind data from a partial reflection D 1 drifts (P.R.D.) system are obtained from two 2-3 h soundings during summer and winter months.

TL;DR: In this paper, effective time constants τ for the conversion of NO+-ions to cluster ions, the most important formation path of cluster ions in the lower ionosphere, were determined from 8 in situ measurements of the composition of positive and negative ions and of neutral gases.

TL;DR: In this article, it was shown that any abnormal reversal of the equatorial horizontal electric field to the eastward direction at night is followed by the occurrence of intense VHF scintillation with a delay in time of the order of an hour.

TL;DR: In this article, a geomagnetic storm was observed during a geostationary satellite deployment on February 15, 1978, and the frequency dependence of the scintillation index was analyzed.

TL;DR: In this paper, a quasi-point heating model was proposed to generate gravity wave induced by the terminator crossing constituent inhomogeneities of short lifetime, and the largest amplitude must appear vertically above the source, where the perturbation frequency is close to the Vaisala-Brunt frequency.

TL;DR: In this article, a scanning spectrometer comprising a large, high resolution Fabry-Perot etalon, a small, low resolution etalon and an interference filter was used for the recording of atomic spectral line emissions from the daytime upper atmosphere.

TL;DR: In this paper, low-latitude geomagnetic micropulsations have been observed at ASO (22°N, 198°E in Geomagnetic coordinate) by use of a superconducting magnetometer, and signals in the period range from 50 to 120 s (Pi2 and Pc4) were analyzed in comparison with ionospheric sounding data.

TL;DR: In this article, the direction of the whistler mode energy in a direction perpendicular to the local magnetic meridian has been observed and measured at an altitude of 500-600 km from two ground-based transmitters at frequencies of 16.0 kHz and 17.8 kHz, respectively.

TL;DR: In this article, the phase-screen theory for scintillation is employed to identify four factors that control the S 4 σ φ ratio, and the behavior of two of them is explored for models describing both sheetlike and rod-density irregularities.

TL;DR: In this paper, a simple surface propagation model coupled with a moments method was used to estimate the effect of a patch of sporadic-E on propagation in the lower ELF band.