Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1981"

TL;DR: In this paper, the authors present theoretical and numerical simulation studies supporting these ideas on equatorial spread-F (ESF) phenomena and show that these irregularities are formed by a two-step process in which they are driven by the steep plasma density gradients created by the primary long wavelength Rayleigh-Taylor type plasma fluid instabilities.

TL;DR: In this paper, radio and radar measurements of vertical and east-west F-region drift velocities at Jicamarca have determined the seasonal and solar cycle variations of the F -region eastwest and vertical electric fields, respectively.

TL;DR: In this article, the effects of E×B drift, both vertical and horizontal, on the equatorial ionosphere were investigated. And the results showed that the results were in good agreement with measured values in the 1900-2400 LT period.

TL;DR: In this paper, the authors reviewed recent observations of equatorial scintillations with an emphasis on GHz measurements and explored the steep spatial gradients observed in in-situ data and their relationship to intense GHz scintillation.

TL;DR: In this paper, the theory of the F-region dynamo, which drives about 10-15% of the total mid-latitude ionospheric current by day, and the major part at night, is reviewed.

TL;DR: In this paper, the major features of the atmospheric circulation predicted to occur following a geomagnetic substorm in the earth's thermosphere are described on the basis of a three-dimensional, time-dependent simulation.

TL;DR: In this paper, a review of ground-based and satellite measurements of the equatorial anomaly has been undertaken, with an attempt to relate the observed differences of the forms of the Equatorial anomaly, throughout the day and from season to season in these zones, with differences of (1) magnetic equator location relative to the geographic, (2) magnetic declination and (3) electric and magnetic fields in the vicinity of the magnetic Equator.

TL;DR: In this paper, the behavior of T sub e at the altitudes of these models is discussed in terms of its implications for our understanding of the energy exchange between the F-region and the plasmasphere.

TL;DR: In this paper, a model based on the typical features of seasonal and geographical variation of tropical convection generating the traveling ionospheric disturbances (TIDs) is presented which can explain seasonal and geographic variations of premidnight equatorial spread-F occurrence.

TL;DR: In this article, an electrostatic probe designed to measure ion density with high time resolution and accuracy was flown on a NIKE-APACHE rocket from Andoya Rocket Range on 1 March 1978.

TL;DR: In this article, the authors review an intense research effort aimed at understanding the large scale disruption of the equatorial F layer which often commences just after sunset, and lasts for most of the night.

TL;DR: In this paper, the spatial power spectrum of intensity fluctuations in a reception plane parallel to the screen is calculated for a plane wave incident upon a thin plane one-dimensional phase-changing screen that has an outer scale Lo, an inner scale Li and an intervening inverse power-law spectrum (spectral index p).

TL;DR: Spaced antenna drifts (S.A.D) experiments with the SOUSY-VHF-Radar are described in this article. But the results of these experiments are limited.

TL;DR: In this article, the effect of the impact of the neutrals on the thermosphere has been studied and a model of the process has been developed, which is based on the pitch angle distribution of the ions in the ring current.

TL;DR: A quasi-two-day oscillation in the meridional winds near 90 km altitude has been observed at Adelaide (35°S) during late summer of the years 1966-1975 as mentioned in this paper.

TL;DR: In this paper, a simplified coupling mechanism was proposed to explain the large-scale variations of the semi-diurnal tide in a non-solar migrating mode through longitudinal changes of the background atmosphere.

TL;DR: In this article, it is suggested that small-scale ionospheric structures (which are undoubtedly also present) are effective in inhibiting some of the specular reflections thus contributing to the diffuse nature of some records.

TL;DR: In this paper, a simple exponential, altitude-dependent equation is used to model the electric field and conductivity of balloon data collected over electrified clouds and thunderstorms, along with a discussion of the thunderstorm-related electric currents.

TL;DR: In this article, the NCAR TGCM was used to investigate the effect of the winds and temperatures on the low-latitude ionospheric F-region at two stations, Huancayo, Peru (1°N dip latitude) and Tucman, Argentina (11°S dip latitude).

TL;DR: A detailed analysis of auroral and magnetic observations made during two substorms shows that the bursts of irregular magnetic pulsations called PiB's are generated at the time of the auroral intensification as mentioned in this paper.

TL;DR: The first VHF radar measurements with height resolution of 300 m and angular resolution of 1.7° were carried out in low latitudes at the Arecibo Observatory, Puerto Rico.

TL;DR: In this article, the results of the first launch point to a uniform neutral atmospheric profile in the presence of extremely irregular bottomside ion distributions, a result which tends to negate the possible role of atmospheric turbulence.

TL;DR: In this article, the relationship between the ionospheric critical frequencies and the sunspot numbers has changed significantly on a secular time-scale, and it is shown that a significant proportion of the solar ionizing flux is associated with photospheric faculae and experiences a time-variation linked to the total facular area.

TL;DR: In this paper, the observations and chemistry of the ionization of the Earth's middle atmosphere, here defined as the region between 100 km and the tropopause, consisting of the D-region (50-100 km) and the stratosphere, are discussed.

TL;DR: In this paper, the autocorrelation functions of the reflected radiowaves (amplitude) were used to calculate a turbulent velocity parameter, and also the related energy dissipation rate from ~ 70-100 km.

TL;DR: In this paper, the phase response was found to be a non-linear function of solar obscuration with a maximum phase deviation which was less than expected when compared with the normal diurnal phase variation.

TL;DR: In this article, the recent additional knowledge about the physical processes in two broad areas of the equatorial electrojet are emphasized 1. (i) the local interactions of the neutral winds with the electrojet plasma which result in diverse but physically inter-related effects on the altitude structure of electric fields and currents, ionization convergences and the formation of blanketing E s layers and F -region ionization dynamics 2.

TL;DR: The mean Doppler frequency (f D ) of the VHP backscatter radar signals from type II plasma irregularities in the equatorial electrojet is a measure of the driving electric field in the electrojet as discussed by the authors.

TL;DR: In this article, a long series of monthly 36 h observations, plus a series of observations at the same local time each day over two months at Arecibo, have been analyzed for tidal structure and variability.

TL;DR: In this paper, a simple model of forced oscillations of the manetosphere is outlined and used to evaluate the temporal variation of the phase pattern over a meridional network of geomagnetic observatories.