Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1996"

TL;DR: In this article, the HWM90 thermospheric wind model has been revised in the lower thermosphere and extended into the mesosphere, stratosphere and lower atmosphere to provide a single analytic model for calculating zonal and meridional wind profiles representative of the climatological average for various geophysical conditions.

TL;DR: The theory of ambiguity functions is summarized and the use of lag profiles as tools of describing arbitrary kinds of incoherent scatter measurements are discussed and a general way to calculate error estimates of estimated autocorrelation function values values is developed.

TL;DR: The most advanced results in previous heating experiments at Tromso have been obtained in the following research areas: 1) Generation of secondary electromagnetic waves at very, extremely and ultra low frequencies by amplitude modulated heating of the polar electrojet current.

TL;DR: In this article, the authors provide an overview of some of the important scientific issues concerning ionospheric-thermospheric weather, with the emphasis on the ionosphere, and provide a brief discussion of weather disturbances and features, the causes of weather, and the status of weather modeling.

TL;DR: In this article, it is shown that a storm recovery can be predicted with remarkable accuracy from measurements made during the first phase of a geomagnetic storm, which is known as the Dst growth phase.

TL;DR: Geomagnetic storm effects at heights of about 0-100 km are briefly reviewed in this article, with emphasis being paid to middle latitudes, particularly to Europe, and correlations with geomagnetic storms seem to reappear in the troposphere.

TL;DR: In this paper, the authors attempt to find the northern hemisphere zonal wavenumber for a striking quasi-2-day wave "event" or "burst" observed near 90 km altitude in the summer of 1992.

TL;DR: In this article, a tutorial review describes some possible future scenarios for changes in temperature and water vapor in the mesosphere-lower thermosphere (MLT) region (50-100 km).

TL;DR: In this paper, an exponential decay model of the variation of the current moment of the source lightning stroke with time was fitted to the measured spectra using an optimisation algorithm, which enabled the magnitude and duration of the continuing currents in 274 unusually large lightning flashes to be estimated.

TL;DR: In this paper, the authors investigated the AGW-TID relationship by means of one-to-one comparison of theoretical model results with EISCAT data for several TID events and found that their use of TID "polarization information" along a single incoherent scatter beam is basically as valuable for the unique determination of a causative AGW as is traditional TID propagation/dispersion information.

TL;DR: In this paper, the first three modes of the vertical electric component have been measured regularly in the Nagycenk Observatory (47.6°N, 16.7°E) since May 1993.

TL;DR: The time variations of the Schumann resonance peak frequencies for the first three modes are presented in the vertical electric component measured in the Nagycenk Observatory (47.6°N, 16.7°E) from May 1993 to August 1994.

TL;DR: In this paper, the vertical eddy diffusivity of K in the tropo-stratosphere and mesosphere has been estimated from a seven-year (1986-1992) database of the echo power spectral width observed by a VHF (46.5 MHz) Doppler radar (the MU radar) in Japan.

TL;DR: In this paper, the authors review the leading wave dissipation paradigms and identify the experimental data required to test definitively the fundamental physics upon which these theories are based, and examine the separability of the joint vertical wave number (m, ω) and temporal frequency (ω) spectrum and the unambiguous two-dimensional horizontal wave number spectrum.

TL;DR: In this article, a new compact formulation of the equation of transfer for a scattering system for a magnetized plasma is given, based on the low temperature kinetic model and accounts for scattering from fluctuations in density, magnetic field, electric field and current.

TL;DR: A review of the current state of comprehensive, three-dimensional, time-dependent modelling of the circulation in the middle and upper atmosphere from a meteorologist's perspective can be found in this article.

TL;DR: The principles of coherent backscatter from irregularities created by plasma instabilities in the ionospheric E-region are described in this paper, and some applications, particularly of auroral radars, are briefly mentioned.

TL;DR: In this paper, the authors discuss some of the principal adverse space environmental effects presently known including trapped magnetospheric radiation, solar energetic particles, geomagnetic storms, and magnetosphere substorms.

TL;DR: The recent development of imaging riometer techniques has enabled a range of new, interesting observations of the complex dynamics of auroral and polar radio wave absorption events as mentioned in this paper, which mostly relate to the precipitation of energetic particles, creating enhanced ionization in the D-region.

TL;DR: In this article, two long mean surface air temperature series are presented for Armagh Observatory; one based on twice daily'spot' temperature readings, 1796-1882, and the other on daily maximum and minimum temperatures, 1844-1992.

TL;DR: In this article, a double-etalon Fabry-Perot interferometer is used to perform high-resolution spectral analysis of the backscattered lidar signal, and to reject the bright background light from the daytime sky.

TL;DR: In this article, an analytic form for the autocorrelation function was proposed based on a Lagrangian description of the diffusion centre's motion. And the turbulent diffusion coefficient, the correlation length and the correlation time associated with the turbulence can be directly estimated by fitting the data with this analytic expression.

TL;DR: In this paper, the relative motions of arcs and ionospheric plasma and the changes of tangential velocity as the plasma traverses the arcs are investigated. But they are interpreted in relation to the current system to which the arc belongs as a trace of an upward-directed field-aligned sheet current.

TL;DR: In this paper, the average amplitude and phase relationship between N e, V i T i and T e was derived from EISCAT data of a quiet daytime F-region from November 1987 to December 1991.

TL;DR: In this article, the authors study incoherent scatter data errors with special emphasis on the situation with good signal-to-noise ratio and derive formulae suitable for the estimation of errors and their covariances.

TL;DR: In this paper, the EISCAT UHF radar system and a low-light level TV camera were used to detect the motion of an auroral arc and its small-scale structures.

TL;DR: In this article, the UHF Common-Programme (CP) data have been searched back to 1986 for coherent echoes, which appear as narrow spectra superimposed on the normal incoherent scatter spectra recorded by the EISCAT UHF and VHF radars.

TL;DR: In this article, the authors analyzed 375 h of Na Wind/Temperature lidar measurements of the mesopause region (≈ 80-105 km) Na density and temperature profiles on 57 nights distributed over 2 yr at Urbana, Illinois.