Clouds of Venus: A Preliminary Assessment of Microstructure

  title={Clouds of Venus: A Preliminary Assessment of Microstructure},
  author={Robert G. Knollenberg and Donald M. Hunten},
  pages={70 - 74}
The multimodal microstructure of the Venus cloud system has been examined. In addition to confirmed H2SO4 droplets and suspected elemental sulfur, a highly concentrated aerosol population has been observed extending above, within, and below the cloud system. These aerosols appear to cycle through the cloud droplets, but can never be removed by the weak precipitation mechanisms present. All cloud particles are likely laced with aerosol contaminants. Sedimentation and decomposition of H2SO4 in… 
The microphysics of the clouds of Venus: Results of the Pioneer Venus Particle Size Spectrometer Experiment
The results of the particle size spectrometer experiment on the Pioneer Venus sounder probe are presented. The vertical cloud structure is found to consist of three primary cloud regions of
The clouds of Venus: A synthesis report
The results presented represent a synthesis of data from those Pioneer Venus experiments directed toward studying cloud problems. These orbiter and multiprobe experiments show the cloud system to
The Structure of the Clouds of Venus: Results of the Pioneer Venus
The results of the nephelometer experiments conducted aboard the four probes of the Pioneer Venus mission are presented. The vertical structure of the clouds exhibits an upper haze region leading to
Photochemistry of SO2 in Venus' upper cloud layers
A model is presented for the distribution of photochemically active gases in and above the upper cloud layer of Venus. Attention is focused on reproducing the experimental results of the Pioneer
Sulfur dioxide in the Venus atmosphere: Distribution and implications
The Pioneer Venus Orbiter Ultraviolet Spectrometer sees variable disk brightness features similar to the well-known "UV markings" seen at longer wavelengths. The bright features are consistent with a
Venus' Spectral Signatures and the Potential for Life in the Clouds
It is suggested that particles in Venus' lower clouds contain sufficient mass balance to harbor microorganisms, water, and solutes, and potentially sufficient biomass to be detected by optical methods, and warrant further investigations into the prospect of biosignatures inVenus' clouds.
Oxides of nitrogen and the clouds of Venus
Nitric Oxide may be produced in the atmosphere of Venus by lightning storms in the clouds. Here we suggest that the odd nitrogen thus formed may play an important part in the chemistry of the clouds.
Techniques for probing cloud microstructure


Clouds of Venus: Particle Size Distribution Measurements
The discovery of large particles > 30 micrometers, significant particle mass loading, and size spectral features suggest that precipitation is likely produced; a peculiar aerosol structure beneath the lowest cloud layer could be residue from a recent shower.
Nature of the Ultraviolet Absorber in the Venus Clouds: Inferences Based on Pioneer Venus Data
Several photometric measurements of Venus made from the Pioneer Venus orbiter and probes indicate that solar near-ultraviolet radiation is being absorbed throughout much of the main cloud region, but
Abstract The size distribution of secondary particulate matter, formed from condensing vapors in meteoric trains in the meteoric evaporating zone, was calculated. The diameters of the particles were
Orbiter Cloud Photopolarimeter Investigation
The first polarization measurements of the orbiter cloud photopolarimeter have detected a planet-wide layer of submicrometer aerosols of substantial visible optical thickness, of the order of 0.05 to
Results of Venus Missions
  • M. Marov
  • Physics, Environmental Science
  • 1978
Although Venus is the planet most similar to the Earth in size, mass, mean density, and the amount of solar energy absorbed (see Table 1 ), for a long time it remained perplexing because even the
Absorption of Sunlight in the Atmosphere of Venus
In this report the fluxes measured by the solar flux radiometer (LSFR) of the Pioneer Venus large probe are compared with calculations for model atmospheres to determine flux profiles consistent with the measurements if an additional source of absorption is included in the upper cloud.
Interpretation of the polarization of Venus
Abstract The linear polarization of sunlight reflected by Venus is analyzed by comparing observations with extensive multiple scattering computations. The analysis establishes that Venus is veiled by
Further Results of the Pioneer Venus Nephelometer Experiment
Backscattering data for the nephelometer experiments conducted aboard the Pioneer Venus mission probes, including data up to the highest altitudes measured by the probes, are presented. A few small
Preliminary Results of the Solar Flux Radiometer Experiment Aboard the Pioneer Venus Multiprobe Mission
The solar flux radiometer aboard the Pioneer Venus large probe operated successfully during its descent through the atmosphere of Venus, implying that about 2 percent of the solar energy incident on the planet is absorbed at the ground.