Showing papers in "Advances in Space Research in 1985"

TL;DR: In this article, a critical comparison and synthesis of data from the four Pioneer Venus Probes, the Pioneer Venus Orbiter, and the Venera 10, 12, and 13 landers is derived.

TL;DR: In this paper, the authors provided models of the Venus neutral upper atmosphere, based on both in-situ and remote sensing measurements, for the height interval from 100 to 3,500 km.

TL;DR: In this article, the role of MHD wave phenomena both as transients and as standing structures in the coupled flow system is discussed, and the physics of the magnetopause flux transfer events are discussed.

TL;DR: In this paper, the time evolution of the near-earth man-made orbital debris environment modeled by numerical simulation is presented, where the current untrackable small objects are assumed to result from explosions and are predicted from data collected from a ground explosion experiment.

TL;DR: In this article, the solar and thermal radiation fields of Venus have been studied and direct measurements and results of numerical models based on direct measurements are presented, with emphasis placed on global energy budget parameters, spectral and angular dependences, spatial distribution, and temporal variations of solar, thermal radiation.

TL;DR: A reference model of the atmospheric circulation on Venus based on available observations is presented in this article, where the reference atmosphere has the following main features: the entire atmosphere below 85 km moves predominantly from east to west in the planet's reference system (in the same direction as the rotation of the solid planet itself) with the possible exception of the lowest 10 km where velocities are low, a jet is present near the cloud-top level at 45 deg latitude in both hemispheres, with a magnitude of approximately 100 m/s, a weak meridional (north-south

TL;DR: In this paper, a summary of the data currently available (June 1984) describing the planet-enshrouding particulate matter in the Venus atmosphere is presented, including a precis of upper haze and cloud-top properties, parameters for model-size distributions for particles and particulate layers.

TL;DR: In this paper, a radiative-convective equilibrium model is developed and applied to study cloud optical thickness feedbacks in the CO2 climate problem, and the sign of the feedback is negative: cloud optical properties alter in such a way as to reduce the surface and tropospheric warming caused by the addition of CO2.

TL;DR: A review of what is known about the surface of Mars from reflectance spectroscopy, including some new results and providing an overview of the principles involved is given in this article, while some form of bound water and/or OH has been known on Mars for many years, a new result presented is the identification of structural OH in a dilute or poorly crystalline magnesian clay.

TL;DR: In this article, a comparison between observed and calculated values of TEC has highlighted the strengths and deficiencies of current models of the N(h) profile of the ionosphere, especially of the F2 region.

TL;DR: In this article, an examination has been conducted of the region of occurrence of flux transfer events for three distinct orientations of the interplanetary magnetic field: nearly horizontal in the solar magnetospheric equator, diagonally southward at 45 deg to the magnetosphere equator and nearly due south.

TL;DR: In this paper, the authors present the current knowledge on the composition of the Venus atmosphere in the altitude range from the surface to 100 km, including CO 2, N2, He, Ne, Ar, and Kr.

TL;DR: Physical properties of the Venus ionosphere obtained by experiments on the US Pioneer Venus and the Soviet Venera missions are presented in the form of models suitable for inclusion in the Venus International Reference Atmosphere as discussed by the authors.

TL;DR: In this paper, the vertical profile of the upward and downward broadband flux of sunlight at a solar zenith angle of 65.7° was used to evaluate the solar heating rate at cloud levels as a function of altitude, solar longitude, and latitude.

TL;DR: In this paper, a series of images of the geocorona in scattered solar Ly-alpha emissions is used to obtain a best-fit spherical model of atomic hydrogen densities in the earth's exosphere; a Chamberlain model provides an adequate fit to radial distances of 4.5 earth-radii, beyond which an exponential fit is used.

TL;DR: In this paper, the trajectories attained by kick motor solid propellant particulates are modeled, and an estimate is made of the number of particles which will remain in orbit after the first year.

TL;DR: In this article, magnetic field signatures of various mass-loading processes are discussed and experimental results from the Pioneer Venus Orbiter magnetometer experiment are examined for evidence of these signatures, which suggest that the acceleration process, stochastic pickup of ionospheric ions, and J(bar XB(bar) force'scavenging' at the ionopause all occur at various times.

TL;DR: In this article, a 10-year Space Debris Assessment Program was initiated to characterize the hazards of orbiting debris, the potential damage to typical spacecraft components, and to identify means of controlling the damage.

TL;DR: The first completed map of the series covers the western equatorial region of Mars as discussed by the authors, at 1:15 million scale, shows more than 60 individual rock stratigraphic units assigned to three Martian time-stratigram systems.

TL;DR: In this paper, a study of the properties of the south-west monsoon system through lower level and upper level thermal structure around the region using NOAA temperature soundings is presented.

TL;DR: In this paper, the implications of atmospheric corrections, bidirectional reflectance, and transformations from narrow spectral bands to the total solar spectrum for albedo derivations are addressed.

TL;DR: In this article, Fourier spectrometers for the investigation of infrared spectra of Venus were installed on the recent Soviet orbiters “Venera-15” and Venera16, with a spectral resolution of 5 cm −1 (ground based processing) and about 7 cm − 1 (pre-processed on board) and a spatial resolution of about 100 km at the Venusian cloud top level.

TL;DR: In this article, the physics of using a radioastronomy receiver as an in-situ detector of plasma, and in some cases of molecules and dust grains is reviewed, and applied to the ICE encounter with comet Giacobini-Zinner.

TL;DR: The Dynamics Explorer satellites have returned a large body of data containing high resolution magnetometer measurements and distributions of charged particles of all but thermal electrons, and the relations of the field aligned currents to particle precipitation structures were investigated and the charge carriers were identified as mentioned in this paper.

TL;DR: In this article, major climate determining processes are outlined and the research priorities are discussed, which are regarded essential to investigate them and their interactions in a complex non-linear manner in different time scales.

TL;DR: In this article, the shape of the dayside Venus ionopause and its dependence on solar wind parameters was examined using Pioneer Venus Orbiter field and particle data, showing a strong correlation between the ionosphere altitude and magnetosheath magnetic pressure.

TL;DR: The International Reference Ionosphere-1979 includes a program for the relative ion composition computation as mentioned in this paper, which is constructed on the basis of the Danilov and Semenov /1/ empirical model, which averaged 42 rocket measurements of the ion composition at middle latitudes below 200 km, on AEROS satellite measurements, and on Taylor's data /2/ above that altitude.

TL;DR: In this article, the authors analyzed the thermal structure data obtained by Pioneer Venus (PV) and used it to make calculations concerning cyclostrophic circulation around Venus, which indicated a balanced zonal circulation with midlatitude jets of peak velocities in the 110-120 m/s range, located between 50 and 40 mb in each hemisphere of the planet near 45 deg latitude.

TL;DR: In this paper, electron temperature data gathered by the AE-C, AEROS, Isis-1 and -2 spacecraft are employed to define linear models for the average conditions, taking of evidence for seasonal, altitudinal, solar activity and density-temperature effects.

TL;DR: In this paper, the problems of combining different data sets are discussed, and examples from a proposed model atmosphere for the stratosphere and mesosphere are presented, given in terms of zonal means and amplitude and phase of Zonal waves 1 and 2 for temperature and geopotential height, as functions of latitude and pressure for each calendar month.