Showing papers in "Planetary and Space Science in 1978"

TL;DR: In this article, it was shown that most of the N2 molecules excited to singlet states in the 12.5-14.86 eV range are depopulated by predissociation and not by the emission of EUV photons and that this is the principal mechanism by which N2 is dissociated by solar EUV absorption and by electron impact.

TL;DR: In this paper, the damping experienced by standing Alfven waves in a dipole magnetic field was investigated and it was shown that typically the normalized damping rate, γ ω, is ∼0.1 for nightside values of conductivity and ∼ 0.01 for the dayside.

TL;DR: In this paper, the authors performed simultaneous measurements of the nighttime atmospheric sodium and potassium layer using a lidar facility set up at the Haute Provence Observatory, where the similarity observed in the behaviour of the spatial parameters of both layers indicates that the same processes are responsible for their day-to-day variations.

TL;DR: In this paper, the characteristic magnetic signatures of magnetospheric substorms both on the ground and in space were determined using daily magnetograms from a midlatitude network of geomagnetic observatories.

TL;DR: In this article, it was shown that the ion-pair production rate above 30 km is directly proportional to the atmospheric number density, which is proportional to a simple power law in number density or pressure.

TL;DR: Moreels et al. as mentioned in this paper derived the intensity distribution of the OH Meinel bands in the airglow from the minor constituent profiles of Moreels et. al. (1977).

TL;DR: In this article, the authors used the estimated abundance of the H+ ions in the upper F-region which can be extracted from the observations to study the exchange of plasma between the ionosphere and the magnetosphere.

TL;DR: In this paper, the coupling between the F 2-layer of conjugate hemispheres during magnetically quiet periods is studied. But the results suggest that there is insufficient time between magnetic storms for complete replenishment of the protonosphere to occur.

TL;DR: In this article, the authors measured the spectra of impact light flashes and estimated the number of atoms vaporized during the impact process, and calculated the temperature of the vapour produced during hypervelocity particle impacts.

TL;DR: In this paper, the photoelectron flux in the ionosphere has been calculated by solving the Boltzmann equation, which is flexible enough to allow for a wide range of energy and angular dependences for both external and internal electron sources.

TL;DR: In this article, a line of magnetometers stretching along a corrected geomagnetic meridian ∼ 302°E through western Canada are used to study the relationship between the convection westward electrojet and Pc 5 micropulsations in the morning sector.

TL;DR: In this paper, an exact integral for the escape flux applicable in marginal cases is found for a simple atmosphere and collisional cut-off for the exobase of a simple Mars.

TL;DR: In this paper, the velocities and relative masses of secondary particles produced during hypervelocity primary impacts were determined as a function of the angle between the ejection direction and the target surface.

TL;DR: In this article, Hartle and Mayr (1977) proposed an alternative mechanism for the night side bulges of H and H2 by strong thermospheric winds, analogous to the Johnson pump for the terrestrial winter helium bulge.

TL;DR: In this article, the excitation mechanism for O 2 (1 Δ) in the night-time is through the reaction between OH∗ and atomic oxygen and the recombination of atomic oxygen.

TL;DR: In this paper, a mathematical model of the steady state polar convective electric field pattern is used in conjunction with production and loss processes to solve the continuity equation for the ionization density in a unit volume as it moves across the polar cap and through the auroral zones.

TL;DR: In this article, the energy spectra of electrons encountered on a rocket flight across an array of auroral arcs are employed to test three related models of electron acceleration, all three are based on a potential difference existing between the source plasma in the magnetosphere and the observation point in the ionosphere.

TL;DR: In this paper, Lam and Rostoker showed that Pc 5 micropulsations can be regarded as LC-oscillations of a three-dimensional current loop involving downward field-aligned current flow near noon, which diverges in part to form the ionospheric westward electrojet and returns back along magnetic field lines into the magnetosphere.

TL;DR: In this paper, the authors have estimated the threshold conditions for the excitation of the unstable waves under various physical circumstances, and for some representative conditions they have also calculated the frequencies, growth rates, and wavelengths for the fastest growing modes using the linear approximation.

TL;DR: In this paper, an historical account of the development of knowledge concerning the processes controlling the emission of the λ 5577 and λ 6300, 6364 lines of oxygen and the −5198, 5201 lines of nitrogen in the nightglow is given.

TL;DR: In this article, the velocity distribution of hydrogen atoms in the terrestrial exosphere was measured as a function of radial distance (up to 7 Earth radii, ER) with the help of a Lyman-α hydrogen absorption cell, flown in 1968 on board the OGO-5 satellite.

TL;DR: The dayside hydrogen exosphere was observed in October-November 1975 with a Lymanalpha photometer carried on board Venera-9 and 10 as mentioned in this paper, which allowed for the first time linewidth measurements.

TL;DR: In this paper, low-altitude satellite observations of precipitated and locally mirroring protons during periods of ground-based SAR arc observations are presented, which can favourably be accounted for by the Cornwall et al. (1971) theory for the SAR arc formation.

TL;DR: In this article, a possible relation between the Type 3 palaeomagnetosphere and palaeoclimate of the Earth during polarity reversals and geomagnetic excursions is suggested.

TL;DR: In this paper, steady-state solutions for the He(+) continuity, momentum, and energy equations have been obtained self-consistently, yielding density, velocity, and temperature profiles of He(+ from 200 to 2000 km altitude.

TL;DR: It is argued that there is a terrestrial loss of hydrogen as ions which includes the polar wind but extends effectively down to a latitude in the range 45-50° invariant.

TL;DR: The dominant response of the terminator is due to the change in thermospheric absorption of solar radiation, and leads to two types of atmospheric waves: (i) a ducted acoustic wave at altitudes below 100 km and (ii) a boundary wave concentrated along the mesopause as mentioned in this paper.

TL;DR: The irradiation solar fluxes between 120 and 400 nm are reviewed and discussed in this paper and disagreements between the recent observations are pointed out, emphasizing the future needs in this wavelength range for aeronomic purposes.

TL;DR: In this paper, the mesospheric upward flux and the Jeans escape mechanism are correlated with other observed variations in the atmosphere; however, no straightforward explanation has been proposed to date.

TL;DR: In this paper, the authors derived a rate constant for quenching of the N 2 (A 3 Σ u +, v = 1) level with O( 3 P ) of 1.7(± 0.8) × 10 −11 cm 3 s −1.