Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1984"

TL;DR: In this paper, a smoothed time series of daily values of the area A(t) of the main vortex, as it appears on isentropic Q maps, is proposed.

TL;DR: In this paper, partial reflection measurements of horizontal winds in the mesosphere and lower thermosphere made at Adelaide (35° S, 138° E) and Townsville (19°S, 147°E) have been spectrally analyzed as functions of frequency and wavenumber.

TL;DR: In this paper, the effect of an electric field and a homogeneous neutral wind on the vertical ion motion in the ionospheric E -region is investigated, and it is shown that a right-handed screw is more effective than a left-handed one with equal pitch in compressing plasma into thin sheets.

TL;DR: In this article, an attempt is made at the statistical analysis of small-scale disturbances in the stratosphere and mesosphere with the aid of meteorological rocket observations at many stations from 77°N to 8°S for several years.

TL;DR: Recent progress in the study of middle atmosphere tides is reviewed in this article, where the role of tides in accelerating and heating the mean flow at the base of the thermosphere, observational efforts which delineate average seasonal, latitudinal and vertical structures of tides, and shorterterm variations of tides about these values, theoretical and observational studies concerning the importance of non-migrating tidal components; the effects of tides on minor constituent concentrations in the upper mesosphere and lower thermospheres.

TL;DR: In this paper, the current status of calculating infrared cooling by CO2 in the mesosphere and lower thermosphere is discussed, and a three-energy-level model is derived for the excited population levels of a CO2 molecule.

TL;DR: In this article, a review of recent studies of the dynamics of the mesopause region using ground-based radars is presented, focusing on observations of prevailing winds, planetary scale oscillations with periods greater than 1 day and gravity wave and small scale motions.

TL;DR: In this paper, the authors measured the scattering of sunlight from the polar mesospheric cloud layer in the 0.2-0.3 μm spectral range and revealed that the brighter clouds are composed of particles with radii up to 0.07 µm.

TL;DR: In this article, the potential of the EISCAT radar system for observing plasma convection patterns at high latitudes has been explored in a preliminary experiment on 27 November 1982, using a beamswinging technique.

TL;DR: In this article, the authors used the Urakawa-Oki earthquake at 0232 UT on 21 March 1982 to detect ionospheric disturbances by a network of HF-Doppler sounders in central Japan.

TL;DR: In this article, the effect of convection electric fields on the velocity distribution functions of high-latitude ionosphere has been studied from a macroscopic and microscopic point of view, and it is shown that the Grad expansion fails to converge rapidly for large electric fields.

TL;DR: In this article, a 3D neutral wind model is developed and used together with an atmospheric model in a gravity-wave ray-tracing analysis, which shows that the thermospheric wind can act as a filter for waves travelling at unfavorable angles to the mean flow, via the mechanisms of reflection and critical coupling.

TL;DR: In this paper, three independent components of the ion velocity vector and temperature in the same scattering volume, at about 300 km, were measured, with EISCAT, and the ion temperatures derived at the three sites are different.

TL;DR: The method of Hibberd is used to study the variability of ionospheric dynamo currents from day-to-day, with solar rotation and with the solar cycle as discussed by the authors.

TL;DR: The theory of the D-region incoherent scatter process and the techniques for coherent scatter radar measurements have both reached sufficient maturity that a synopsis of this area for the middle atmosphere community is appropriate.

TL;DR: In this paper, a discussion is given of gravity wave saturation and its relation to eddy diffusion in the middle atmosphere, focusing on the saturation process and some of its observable manifestations.

TL;DR: A survey of recent developments in the observation of wind and turbulence in the stratosphere and mesosphere using MST radars is presented in this paper, where the authors highlight the growing recognition that the MST/ST radar is a valuable tool for routine monitoring of the atmospheric wind field.

TL;DR: In this paper, the characteristics of ELF generation produced by modulation of the dynamo current system from HF heating of the ionospheric D-region are described and stepped ELF frequency observations are shown to support the model assumptions.

TL;DR: In this paper, a new incoherent scatter radar facility, EISCAT, is described and its capabilities for performing high-latitude upper atmosphere research are described, as well as its capability for conducting high-level radar experiments.

TL;DR: In this paper, the millstone hill incoherent scatter radar was operated to observe the F-region over Canada along the path of the total eclipse of the sun, and electron density, ion temperature, electron temperature and ion line-of-sight drift were measured.

TL;DR: In this paper, a global circuit model is constructed to study responses of air-earth current and electric field to a variation of atmospheric electrical conductivity profile, including the orography and the global distribution of thunderstorm generators.

TL;DR: In this paper, the authors used the reciprocity technique to evaluate the efficiency of excitation of the Earth-ionosphere waveguide by an extended ionospheric current source and found that radiated powers ranging from a few milliwatts at 100 Hz to a few watts at 2.0 kHz can be expected for HF effective radiated power of 150 MW.

TL;DR: In this article, the role of gravity waves for the momentum and heat budget of the atmosphere between approximately 70 and 110 km height is considered, and the authors focus on the dissipation of perturbation kinetic energy and its contribution to the heat budget.

TL;DR: In this paper, a partial reflection drifts system for the measurement of winds in the mesosphere and lower thermosphere was installed as part of the New Zealand Antarctic Research Programme at Scott Base (778 S, 1667 E) Ross Island, Antarctica The wind speed and direction are measured once an hour from echoes available at the time within a height range of 67-97 km.

TL;DR: In this paper, a comprehensive formula for the photochemical time constant of minor constituents in the middle atmosphere is worked out for evaluating the time constants for families of some chemical species that are strongly coupled by rapid exchange reactions.

TL;DR: The EISCAT incoherent scatter radar, operating in a full tristatic mode, provided data on the ionospheric plasma drift above northern Scandinavia, during the 24 h period, 11 UT 25 November to 11 UT 26 November 1982 as mentioned in this paper.

TL;DR: In this paper, the authors demonstrated that the auroral radio absorption measured with a riometer can be predicted from energetic electron measurements at geosynchronous orbit with GEOS-2.

TL;DR: In this paper, a review of recent theoretical and observational studies of middle atmosphere electrodynamics is presented, focusing on observations of large electric fields in the mesosphere and stratosphere which suggest magnitudes of about one volt per sq m.

TL;DR: In this paper, the authors compared the ozone profiles obtained from an MRS and a Dobson instrument (Umkehr) over a time period of approximately four months and found that the microwave measurements yield ozone concentrations which are 20-30% higher than the Umkehr values.

TL;DR: In this article, the authors used a fast-swept gain technique on an ionosonde to support the idea that mid-latitude spread-F irregularities are large-scale wave-like structures.